While star players get a bulk of the attention — as well as blame and credit — during the postseason, there is always a Cinderella story that pop on MLB teams that make a deep run.
Last year, it was Tommy Edman, who spent most of the season on the injured list, then went on to become NL Championship Series MVP for the Los Angeles Dodgers with a .407/.393/.630 slash line, driving in 11 runs in the six-game win over the New York Mets. Houston Astros shortstop Jeremy Peña was a rookie in 2022 when he earned NLCS MVP and World Series MVP. Similarly, Eddie Rosario of Atlanta (2021) and Howie Kendrick of the Washington Nationals (2019) took home NLCS MVPs, while Steve Pearce of the Boston Red Sox was MVP of the 2018 World Series.
Not all X factors need to become MVPs. Some are more unsung because of their natural role, but either come through with a big hit or pitch out of multiple key jams in a series. Injuries will also bring an X factor to the forefront.
Who will be an X factor in 2025? Let’s take a look at all the postseason teams to find out.
National League
Milwaukee Brewers: 3B Caleb Durbin
When the Brewers made the three-player trade that sent closer Devin Williams to the New York Yankees in exchange for left-handed starter Nestor Cortes and Durbin, no one thought the speedy and diminutive infielder would be the best player in that deal — at least for this season. Durbin started the season at Triple-A, but earned an early call-up and eventually took command at the Brewers’ biggest glaring need entering the season at third base.
The worry with Durbin was not his offense, but whether he had the arm to handle third base. While not flashy, Durbin has been surprisingly good at the hot corner. Durbin has committed just six errors this season (one of the lowest totals among qualified third basemen), with only two being on throws.
But Durbin has also had a knack for coming up with a big hit. He finished his first MLB season with a .256/.334/.387 slash line, hitting 11 homers with 18 steals. Durbin also had 25 doubles among his 114 hits.
Philadelphia Phillies: RHP Orion Kerkering
Kerkering came up with a lot of hype in 2023 and has lived up to it while fulfilling a setup role in the Phillies’ bullpen. Kerkering has purely been a one-inning or less guy, only going past one inning in two career appearances. But he has been very effective despite his numbers taking a slight hit due to a more prominent role this season.
The only Orion in MLB history has a 3.30 ERA with a 24.4% strikeout rate and 10.2 walk rate. Those are down from last year’s 2.29 ERA, 28.8% K rate and 6.6% walk rate. Kerkering has been a seventh- or eighth-inning guy this season after coming in earlier in 2024. To wit, Kerkering has picked up his first four MLB saves this season. This year’s walks have been a bit of an issue, but when he is on, the back three of Kerkering, Matt Strahm and Jhoan Duran are among the better trios. Also, with left-hander José Alvarado not able to pitch in the postseason due to his 80-game suspension for performance-enhancing drugs, Kerkering’s role becomes that much more prominent. Kerkering pitched in all four Phillies NL Division Series games last year and seven of 13 playoff games in 2023, so a big workload won’t be surprising.
Los Angeles Dodgers: CF Andy Pages
Yes, it is hard to find an underdog candidate on the defending World Series champions and their massive payroll, but Pages is as close as you are going to get without going to a bench player. After mixed results as a rookie in 2024, Pages has emerged as a steady player with pop in 2025. He has been the Dodgers’ primary center fielder.
Much like 2024, Pages has hit very well against left-handed pitching, posting a slash line of .272/.313/.461. While his average is better vs. lefties, his power is the better tool when facing right-handers as 24 of his 27 homers having come vs. righties. He tends to hit in the bottom third of the lineup, which is usually when opposing pitchers try to take a breath. I do have one other possibility for an X factor and that would be backup catcher Ben Rortvedt, who could see action if Will Smith can’t go because of the hairline fracture in his hand.
Kelly emerged as the primary catcher after opening the season in a job-share situation with Miguel Amaya. Of course, it helped that Amaya, the Opening Day catcher, has had two noteworthy injuries this season and will be available for the playoffs. But isn’t that the case for a Cinderella story? Kelly has handled a good Cubs pitching staff and not been a black hole offensively.
In fact, Kelly, who made his MLB debut at 21 in 2016, is having his best offensive season thanks to his most sustained playing time since 2019-22 with the Arizona Diamondbacks. He hit a career-best .249, while his OBP of .333 is the third-best mark of his career and his slugging percentage of .428 is second-best. Kelly can be a bit streaky from a power perspective. While he does have three two-homer games among his 17 homers this season, he also had two months (June and August) where he didn’t go deep once. He would be a prime candidate for a postseason two-homer game.
San Diego Padres: 1B Ryan O’Hearn
Everyone has their motivations, whether they be real or just buried somewhere in their mind, but yet very recognizable to the average person. That brings us to O’Hearn, who was acquired from the Baltimore Orioles at the trade deadline to bring an offensive boost to the Padres at first base. O’Hearn was available to be dealt because he is an impending free agent.
With a potential big payday in the offing, O’Hearn was slashing .283/.374/.463 with 13 homers and a career-high 134 OPS+. But since joining the Padres, he hasn’t produced, posting a slash line of .276/.350/.387 and an OPS+ of 105. His combined 17 homers matches his career high from 2024 and O’Hearn fits the profile as someone to come through in the clutch for a playoff team.
Cincinnati Reds: 1B Sal Stewart
Stewart just seems to have that intangible spirit about him where he is going to be a thorn in the side of NL Central teams for years to come. A rookie with just 18 games under his belt, Stewart was primarily a third baseman at Double-A and Triple-A this season before getting the September call-up. Most of his action in September has come as a first baseman and he has posted a slash line of .255/.293/.545 with five homers and eight RBIs.
Some rookie always seems to rise the occasion during the postseason and launch the rest of his career. Stewart, the Reds’ No. 4 prospect and No. 84 in all of baseball by Baseball America, has the persona and energy that only elevate the performance of his teammates. The 21-year-old, a first-round draft pick in 2022, certainly produced in the minors, with a .309/.383/.524 slash line with 20 homers and 80 RBIs.
American League
Toronto Blue Jays: CF Daulton Varsho
While Varsho is a household name to most baseball fans, his production hasn’t lived up to they hype that surrounded him. But everybody finds their role and Varsho, once a catcher who played the outfield, has entrenched himself as the Blue Jays’ center fielder. And for postseason purposes, that gives him an advantage for jumping into the spotlight.
Varsho, who has been limited this season due to injuries, is a dynamic defender who won his first Gold Glove last season, helping him post a career-best 5.0 bWAR. Yet he also provides a punch offensively. Varsho has hit 20 homers in just 71 games, matching his 2023 output in 158 games and surpassing last year’s 17 in 138 games. His slash line isn’t beautiful at .238/.284/.548, but his power has allowed him to post a carer-best OPS+ of 122.
Seattle Mariners: DH Jorge Polanco
Polanco is one of those players you don’t really notice — until it is too late. Another reason why many might not know much about Polanco is that he played the first 10 seasons of his career with the Minnesota Twins and just completed his second regular season with the Mariners. Not exactly teams that get a lot of coverage.
Polanco has the credentials to warrant more attention, having posted a 33-homer, 98-RBI season with the Twins in 2021, while being a steady middle infielder, shifting over to second base in recent seasons. A knee injury cut short his 2024, but he has bounced back in 2025, primarily as the Mariners’ designated hitter. He has slashed .265/.326/.495 while hitting 26 homers, the second-most of his career, and driving in 78, his third-highest total. With other key offensive contributors such as Cal Raleigh, Julio Rodríguez and Randy Arozarena in the lineup, Polanco is easy to overlook, which makes him a dangerous player in the postseason.
Cleveland Guardians: SS Gabriel Arias
On a team that has been an offensive black hole this season, Arias fits right in. Seeing his most extensive action since his MLB debut in 2022 and developing into the full-time shortstop as the season progressed, Arias is slashing a paltry .220/.274/.363. But he has committed just five errors at shortstop since late July. His defense is the most important attribute he brings to the Guardians’ lineup.
When Arias does hit, he makes an impact. Of his 95 hits, 37 have gone for extra bases. His 11 homers are one more than his previous career high set two years ago in 126 fewer plate appearances. But he has also seen his doubles total go from 15 to 25 in those same seasons and his RBIs jump from 26 to 54. As such, it just takes a hit here or there from an unsuspecting source to go along with some defense to make a cult hero.
New York Yankees: SS Anthony Volpe
Volpe has been the subject of a lot of criticism this season, only to have some of that couched when it was revealed he has been playing with a bum left shoulder for most of the season. Volpe has been the subject of much anticipation since breaking in as the Yankees’ shortstop in the 2023 season, but this season has been the complete opposite for him. He had the worst of his three seasons, slashing .212/.272/.391, even though his 19 homers were just shy of the 21 he hit as a rookie. His stolen bases have been down and his defense is what has been his biggest deficiency this year, something that can be attributed to an injured left shoulder.
But the postseason is often a chance for a player to reset and no player needs a clean slate like Volpe, who did sit more often during the end of the season to help clear his head. Hitting at the bottom of the order already takes pressure off of him, so anything he does will make the Yankees’ offense that much more formidable.
Boston Red Sox: CF Ceddanne Rafaela
If you ask Red Sox fans about Rafaela, you are going to run the gamut when it comes to the responses. Some love him, some tolerate him and some think he should be in Triple-A. But he is a key part of the roster because of his defense and versatility. Not only can he play a Gold Glove-caliber center field, but he brings that glove to second base on occasion.
Meanwhile, his offense is why fans get down on him. Rafaela slashed .249/.295/.414 this season, resulting in an OPS+ of 95. He has been a more disciplined hitter, walking slightly more and striking out slightly less in his second full season in the majors. Speed works well in the playoffs and if Rafaela puts it together for a couple weeks, the Red Sox could be a force.
Detroit Tigers: UTIL Javier Báez
Baez isn’t listed as a starter at any position on the Tigers’ official depth chart, so you never know where he is going to pop up on the lineup from day to day. But that has been part of the renaissance of Baez this season. He has embraced the role of being versatile, not only playing his natural position of shortstop, but also seeing considerable action in center field, a spot he had never played before this season.
He earned a trip to the All-Star Game with his first-half performance, an honor he hadn’t had since 2019 in his heyday with the Cubs. That was because of his .275/.310/.442 slash line with 10 homers. But the second half of the season has been different, producing only a .223/.230/.318 slash line with two homer, although he was warming up at the end of the regular season. Once baseball’s bad boy, Baez has endeared himself to fans with his performance in 2025. Some postseason magic could earn a lot more goodwill to a greater baseball audience.
