How Luis Severino and the Other MLB Reinforcements Could Play Postseason Hero

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Sometimes, a key post-September call-up or player returning from injury can be the difference in a deep playoff run

On Tuesday night in New York, Luis Severino blanked the Angels for four innings and 67 pitches, allowing two hits and striking out four batters. Although the Angels’ late-season lineup—which lacked Mike Trout, Shohei Ohtani, Justin Upton, and Tommy La Stella—didn’t muster much of a challenge, Severino looked more or less like his usual self, pumping high-90s fastballs and inducing nine swinging strikes in his final three frames. When Severino, who ranked fifth in FanGraphs WAR among all pitchers from 2017-18, signed a four-year, $40 million extension in February, it wouldn’t have seemed surprising for him to be mowing down hitters at the end of the season. But the righty was scratched from his first spring training start with rotator cuff inflammation, and a subsequent lat strain prevented him from facing big league hitters until September 17—just in time for a few pre-October tune-ups.

Severino was one of three pitchers who returned to the Yankees this week after being sidelined all season, although the other two 2019 debuts didn’t go so smoothly. Lefty Jordan Montgomery, a Tommy John survivor who hadn’t pitched in the majors since May 1, 2018, allowed three runs in two post-opener innings on Sunday, and righty Dellin Betances, who missed most of the year with a shoulder impingement, struck out both of the hitters he faced in relief of Montgomery but partially tore his left Achilles tendon in the process. Betances, who led all bullpen pitchers in strikeouts from 2014 to 2018 and trailed only teammate Aroldis Chapman in reliever WAR over the same span, could have become another key cog in Aaron Boone’s formidable bullpen, but the injury ended his season as soon as it started. Montgomery is unlikely to make a major impact in October, although Boone hasn’t ruled out his inclusion on the playoff roster. However, a healthy Severino would be a boon to a patchwork Yankees staff whose starters—including Domingo Germán, who was placed on administrative leave on Thursday after violating MLB’s domestic violence policy—have collectively pitched poorly in the second half.

The Yankees set an MLB record for the most players sent to the injured list in a single season, but they aren’t the only contending team that’s received September reinforcements who hadn’t previously been sighted this season. A’s southpaw Sean Manaea, who led Oakland’s 2018 rotation before succumbing to a torn labrum last August, returned on September 1 and has held his opponents to one run in three starts and 18 frames so far, possibly putting him in position to start the AL wild-card game if Oakland’s lead holds up. Brewers reliever Brent Suter, another recently returned lefty with a fresh UCL, has allowed only one run in his 12 1/3 innings, trailing only Josh Hader among Milwaukee pitchers in September WPA. Formerly injured Rays pitcher Anthony Banda and Mets infielder Jed Lowrie were also recalled or activated this month, although neither is likely to appear in the postseason even if their teams do.

Returning veterans Severino, Manaea, and Suter compose only a partial list of late arrivals who might make their presence felt in the playoffs, because some potentially playoff-bound clubs have also been bolstered by rookies who’ve been promoted since rosters expanded. Dodgers top prospect Gavin Lux, who raked in Double-A and tore up Triple-A before his promotion, has started most of L.A.’s games in September at second base. Oakland’s top prospect, southpaw Jesus Luzardo, has looked good in two three-inning relief outings; in both of those games, he threw to Sean Murphy, another highly touted rookie who’s bogarted time from Oakland’s weak catching corps and hit .353/.389/.853 in 12 games. Flamethrowing Twins righty Brusdar Graterol has touched or topped 100 mph nine times since September 14; Cleveland reliever James Karinchak struck out three of the first four MLB hitters he faced after recording a 58 percent strikeout rate in the minors this season; Astros first-rounder Kyle Tucker has hit well while starting sporadically in the outfield corners; and Rays speedster Johnny Davis, plucked out of the Mexican League, auditioned for playoff pinch-running duty with a first-at-bat triple.

Players who didn’t suit up for a certain major league team before September are still eligible for that team’s playoff roster if they joined that organization by August 31, provided they replace a player on the injured list who has served the minimum amount of time required for activation (for example, a player on the 60-day injured list who’s been on the IL for at least 60 days). That loophole has allowed a lot of players who were absent for most of the year—some of whom had never been in the big leagues before—to play prominent roles at the most important point in the season. The freshest faces on this year’s playoff teams will be trying to channel the successes of a few past standouts in similar situations, whose heroics we can quantify with a stat called championship win probability added (cWPA). Unlike regular WPA, cWPA measures a player’s cumulative contribution toward winning a World Series instead of toward winning a single game.

According to data provided by Baseball-Reference’s Dan Hirsch, 96 players since World War II have made their MLB season debuts on or after September 1 and gone on to accumulate cWPA in postseason games. Two of those players did it twice: Terrance Gore in 2015 and 2018, and Andre Ethier in 2016 and 2017. (The complete list is here.) A few others, like Mark Kiger in 2006 and Kevin Kiermaier in 2013, played in the postseason after not playing in big league games before September but did not amass postseason cWPA because they appeared only as defensive replacements. Since the playoffs expanded to 10 teams in 2012, fewer than five players per season, on average, have earned postseason cWPA despite making their season debuts after August. The record for a single season is seven, set in 2014, when the crop included Hunter Strickland (who allowed six homers in 8 1/3 innings) and 2014 draftee Brandon Finnegan (who pitched pretty well until taking the loss in World Series Game 4). This year’s playoff field may match or surpass seven, depending on how the remaining pennant races resolve.

The table below lists the 14 qualifying players with at least 25 postseason “plays” (for cWPA purposes, “plays” includes all plate appearances, pitching plays, and baserunning plays in which the player was the lead runner). These are the post-September players who got the most playoff face time, although not all of them ultimately helped their teams’ causes.

The next table lists the 18 players whose postseason contributions raised their teams’ chances of winning the World Series by at least 1 percent. Some of the players from the first table appear on this table too, but we also see some new names who made meaningful differences despite little exposure. The Phillies’ Jackie Mayo, for instance, made only one plate appearance in the 1950 World Series, but it was a pinch-hit leadoff walk in the 10th inning of Game 2, with his team trailing by one in the game and the series. (The Phillies lost, but he helped their chances.) Quintin Berry, who played the designated speedster role for the Red Sox in 2013, didn’t make a postseason plate appearance that year, but he earned his ring by stealing one base in each playoff series without being caught.

As one might imagine, jumping from the relatively low-pressure environment of the minors to the thick of a pennant race and the crucible of October can be an intimidating, if exhilarating, transition. “The whole thing about playing is to make it as cold/mathematical as possible, which you learn bit by bit as a pro,” says former Tampa Bay Ray Fernando Perez, who made his major league debut on September 5, 2008, and saw action in all three playoff rounds that October, going 1-for-9 in two starts and pinch running in three other games. He continues, “This cool recedes a bit maybe every time you do something new—first time in big league camp or first time in the big leagues or first time in the playoffs or first time facing someone whose baseball card you have.” When Perez vaulted straight into a pennant race, he says, “I felt I had to relearn the game in the big leagues because you’ve never played with that much adrenaline. ... [It] kind of feels like waaaaay too much coffee.”

Perez pinch ran in World Series Game 5, representing the tying run on first with the Rays down to their last two outs in the series. In that situation, a steal attempt is expected and a caught stealing is incredibly costly, which could have gotten in his head, even though he knew that Phillies closer Brad Lidge was slow to the plate and catcher Carlos Ruiz couldn’t cut him down if he got a good jump. But he says that he and manager Joe Maddon had “talked quite a bit about the right attitude that can make you comfortable quicker,” which Perez sums up as “Err on the side of aggressive.” Although Perez describes the pressure to swipe second as “11/10,” he notes that “Joe was so matter-of-fact about it that it was quite calming.” Perez made it safely into scoring position, but Ben Zobrist and Eric Hinske didn’t drive him in, and the Rays went home unhappy.

There’s not a lot of precedent for rookie position players like Perez—or this year, like Lux or Murphy—making their marks in October almost immediately after making their major league debuts. It’s not unheard of for top non-pitching prospects to make playoff rosters after being summoned to the Show for the first time in September: Javy López did it in 1992, as did Jesús Montero in 2011, Jurickson Profar in 2012, and Corey Seager in 2015. Not long after Seager’s playoff debut, Adalberto Mondesi became the first player to make his major league debut in the World Series (no pressure, rook). But few raw rookies have received regular October playing time and made the most of it, although Xander Bogaerts, who posted a near-.900 OPS in 34 postseason plate appearances in 2013, would have ranked high on the leaderboards above if he’d made the majors about two weeks later than his August 20 debut.

The best examples of position players who did damage in the playoffs after missing the months before September are old guys in their last seasons: Darryl Strawberry in 1999 and Andre Ethier in 2017. Strawberry hit 24 homers in 101 games in 1998 but missed the playoffs after being diagnosed with colon cancer. The following April, he was arrested on charges of cocaine possession and solicitation of prostitution, pleaded no contest, and was suspended for 120 days. He returned in time to triple-slash .327/.500/.612 in 66 plate appearances after September 1, which earned him a part-time playoff role. That October, the 37-year-old Strawberry sent the Yankees to the ALCS by slamming a first-inning, opposite-field, three-run shot that supplied all the scoring in ALDS Game 3, then pulled another homer off the Pesky Pole in ALCS Game 4.

Ethier missed most of 2016 with a fractured tibia and most of 2017 with a herniated disk, but both times he returned in September, made the playoff roster, and went deep against the Cubs in the NLCS, with the bigger blow being his game-tying solo homer in the second inning of 2017’s NLCS Game 3. The 35-year-old career Dodger also added a run-scoring pinch-hit single in World Series Game 7, in his final MLB at bat.

For starters such as Severino and Manaea, the recent example to emulate is Marcus Stroman, who tore his ACL in mid-March 2015, received a season-ending prognosis, and defied doctors’ expectations by making it back to a major league mound for the Blue Jays on September 12, following two minor league rehab starts. Stroman threw 78 pitches in his first MLB outing and worked his way up to 104 by his fourth and final regular-season start. In the playoffs, the leash was off, and Stroman made three starts, two of which Toronto won, including the decisive fifth game of the ALDS. Only David Price—who was unavailable for that clincher after a perplexing, 50-pitch relief outing in Game 4—threw more innings for the Blue Jays during that postseason run.

Speaking of Price: Keep a close eye on present-day pitchers like Luzardo and Graterol, because the greatest October heroics by past players who debuted after August have come from relievers like Francisco Rodríguez, Price, and Julio Urías, all of whom were 23 or younger during the postseasons in question. Price and Urías were top-tier prospects before they achieved October renown, but Rodríguez, perhaps the best-known pop-up playoff pitcher, seemed all the more spectacular because he kind of came out of nowhere.

Signed as an undrafted amateur free agent in 1998, Rodríguez was deemed Baseball America’s no. 71 prospect heading into 2001, but he suffered elbow and shoulder injuries that season and fell off of the list in 2002, when he moved to the bullpen. He started the season in Double-A, struck out 120 batters in 83 innings between Double-A and Triple-A—an arresting strikeout rate in today’s high-strikeout era, let alone in 2002—and made his major league debut on September 18, as MLB’s youngest pitcher. “Rodríguez, 20, could develop into the setup man for [Troy] Percival as soon as next season,” the Los Angeles Times said on September 19. Next month would have been a better guess.

Although the Angels had hesitated to promote him, they couldn’t do without him after he faced 21 hitters and struck out 13 of them in five September outings, allowing two walks, three hits, and no runs. In his first playoff outing, in ALDS Game 2, Rodríguez blew a save in the sixth on a two-run Alfonso Soriano homer, but he stayed in to pitch a scoreless seventh, got the win, and was off to the races. From October 4 (ALDS Game 3) through October 20 (World Series Game 2), K-Rod pitched 11 scoreless innings over seven games, allowing two hits and four walks and racking up 18 strikeouts. On the last day of that run, Rodríguez—who hadn’t won a game in the bigs before October—was credited with his fifth win of the playoffs.

Rodríguez didn’t throw the hardest—his 93.5 mph average fastball velocity in the regular season didn’t quite crack the top 30, even in 2002—but the combination of that moving heater and his wicked curve (which was one of the fastest) made him almost untouchable for hitters who hadn’t seen him. Although Rodríguez rivaled the Rally Monkey as a phenomenon that month, his cWPA doesn’t stand out because of his record in World Series games 4 and 6. In the former, Rodríguez took the loss after yielding an unearned run in his third inning of work; in the latter, he allowed two more runs in 2 2/3 innings, surrendering a dinger to Barry Bonds. But he recovered to strike out the side in Game 7, passing the ball to Percival for the series-ending save. That game raised his 2002 innings total across all levels to 107 2/3, and his 18 2/3 postseason innings easily led all playoff relievers.

Price, the first overall pick in the 2007 draft, was BA’s 10th-ranked prospect entering 2008. He worked exclusively as a starter in the minors that season, climbing from High-A to Double-A to Triple-A. In Durham he was hittable and showed shaky control, but the Rays, who were good for the first time in franchise history, brought him up to the big league pen on September 14. Price didn’t pitch in the ALDS, but the Rays relied on him heavily in the next round. In ALCS Game 2, Price entered in search of the last two outs in the top of the 11th and earned the win when the Rays scored in the bottom half of the frame. In Game 7, he recorded a four-out save to send the Rays to the World Series. Only Price’s teammate Matt Garza posted a higher cWPA during that year’s championship round. Price also finished World Series Game 2 after entering in the seventh, another reminder that previous playoff experience is often overrated. All in all, Price produced the highest postseason cWPA of any player with a September season debut and established a fleeting reputation for playoff clutchness that he wouldn’t restore until 2018.

Unlike Rodríguez and Price in 2008, Urías wasn’t a rookie when he excelled last October. The lefty had become the youngest pitcher ever to start a postseason game in 2016, but he tore the anterior capsule in his left shoulder in 2017, which kept him off the mound for more than a year. Still only weeks past his 22nd birthday, Urías returned to the majors last September but threw only four innings in three regular-season games. The Dodgers left him off the NLDS roster, but they made the surprising decision to take him to the NLCS, even though he hadn’t pitched in almost two weeks by the time that series started. Urías rewarded them with a scoreless 13th in Game 4, which helped him and his team earn a win, and he also turned in a scoreless 17th in a marathon World Series Game 3, cementing a postseason cWPA that’s second only to Price’s in the post-August group.

This season’s pool of players-come-lately who’ve thrust themselves into October consideration is shaping up to be both big enough and talented enough to produce another legendary run. Maybe this year’s most momentous late launch will be by an IL escapee whose body began to cooperate just in time to salvage a lost season. Maybe it’ll be by a first-year player with a glorious future ahead of him, announcing his entrance in unforgettable fashion. It’s the full-season stalwarts who propel teams to this point. But some of October’s most pleasing stars are the kind we can’t see coming until September rolls around.