2026 MLB playoff X-factors: One under-the-radar potential hero for every team

After a grueling 162-game schedule, the MLB postseason is finally here. We’ve got four Wild Card Round series this week, all of which are best-of-three matchups. I can’t wait.

The stars often shine the brightest in the postseason, but other players will need to step up as well. With SeatGeek serving as the Official Ticket Marketplace of MLB, we’ve kept a close eye on all 12 playoff teams, and we’ve identified one underrated X-factor player for each squad. 

Under-the-radar American League X-factors for the 2026 MLB playoffs

These aren’t necessarily the biggest names on their teams, but each could play a major role in deciding how far his club goes this October.

Tampa Bay Rays: OF Chandler Simpson 

The Rays have a great team. The pitching staff has been excellent, and Bryan Baker is a lockdown closer who has had an incredible 2026 campaign. Offensively, opposing pitchers will be focused on the dynamic trio of Yandy Diaz, Jonathan Aranda and, of course, Junior Caminero, but Chandler Simpson is the kind of guy who can take over a playoff series.

Simpson is an elite speedster. He hit over .300 this year while swiping 46 bases. That kind of production can be critical in a postseason game, especially late. Interestingly enough, the Rays don’t utilize Simpson as a leadoff hitter, but rather hitting fifth. It’s a notable strategy, but it’s clearly worked for them.

Regardless of where Simpson hits in the order, he’s going to be a top player for the Rays’ opposition to play against. He’s a great hitter in his own right who puts a ton of pressure on defenses, but his speed on the bases to get steals and put himself into scoring position could prove monumental in Tampa Bay’s playoff run. 

Cleveland Guardians: OF Jo Adell

The Guardians made an interesting move at the deadline to add Adell to the lineup, but it makes sense why they did. Cleveland’s lineup wasn’t – and really still isn’t – known for swatting home runs, but many of the best teams in October come up with big homers. Adell certainly has the power to help the team’s lineup.

Adell is the Guardians’ best pure power guy, and he ended 2026 with 23 homers, seven of which came with Cleveland. The Guardians have a lot of guys who can get on base and do some great things there, but they will need some thump if they’re to make a deep run. Adell had 95 RBIs this year as well, so he doesn’t just need to hit the ball out of the yard to help his team score runs. 

Adell is a bit boom-or-bust given how many strikeouts he racks up, but it takes just one big swing to turn things in his team’s favor. 

Houston Astros: RP Bryan Abreu 

The Astros have the likely AL MVP in Yordan Alvarez, as well as postseason heroes in Jose Altuve and 2022 World Series MVP Jeremy Pena, but a lot of playoff games and series come down to the pitching, particularly the bullpen. The Astros have an elite closer in Josh Hader, but Abreu could be even more of an X-factor.

The veteran right-hander has dynamic stuff, and he’s a proven playoff contributor. He owns a 2.49 ERA in 21 postseason appearances, and in the Astros’ 2022 World Series run, he pitched 11 1/3 scoreless innings in 10 appearances.

The good news for Houston is Abreu has gotten back to top form after a dreadful start to 2026. He had a 5.81 ERA and an opponent OPS of .870 in the first half. Opponents have a sub-.600 OPS off him in the second half, and Abreu also has a sub-2 ERA.

With Hader locked in as the closer, Abreu will be tasked with getting key leverage outs late in games against Chicago in the Wild Card Round. Given the bats the White Sox have, Abreu’s role is a major one to watch this week. 

New York Yankees: IF Jazz Chisholm 

The real X-factor for the Yankees’ playoff run and the Wild Card Round specifically is Aaron Judge, who landed on the IL once again, this time with a calf strain. While it was initially believed he’d miss this round, Judge has said he’s aiming to play. We will see. 

But Chisholm has to step up for New York whether or not Judge plays. The veteran infielder is a dynamic talent with plus power and elite speed. He’s been essentially an average hitter this year with a low-.700s OPS and 19 home runs, though he has swiped 41 bags. 

Chisholm has the talent to take over any given game or series, but he’s been a bit too inconsistent this season to be a reliable go-to guy. He has been better this month, though, after an IL stint for a wrist injury. If things click in October, that would be a major boost for the Yankees’ lineup. Additionally, Chisholm is a pending free agent, so his October performance could help him this coming offseason. 

Boston Red Sox: SP Ranger Suarez 

It looks like Suarez will be slotted into the No. 3 spot for the Wild Card Round in New York, so he would be tasked with starting for Boston in a winner-take-all clash. 

If I’m the Red Sox, while I’d love to get him out there for one of the first two games, first, they’re in good shape with Payton Tolle and Sonny Gray for Games 1 and 2, and second, Suarez is absolutely the guy I’d want getting the nod in a do-or-die game.

The veteran lefty signed a big deal to join Boston this offseason, and it’s worked out very well for both parties. He posted a 3.22 ERA over 28 starts. But October is where Suarez thrives. He was a hero of many Phillies playoff teams in recent years. 

In 11 postseason appearances (eight starts), Suarez has worked 42 2/3 innings and pitched to a 1.48 ERA. He’s been excellent in big moments starting and coming out of the bullpen, and that kind of October experience could prove very useful should the Wild Card Round need a Game 3 as it’s in New York at Yankee Stadium. And should Boston advance to the ALDS and beyond, Suarez should be in line to be a major contributor as well.

Chicago White Sox: OF Randal Grichuk

The White Sox are a young team, so naturally we’ll highlight one of their oldest players. 

Grichuk is a role player for Chicago, but he’s darn good in that role. Grichuk is a right-handed hitting outfielder who gets nearly all of his at-bats against lefties. Grichuk OPSed nearly .900 on the year, and he OPSed over 1.000 off lefties with 11 of his 14 homers coming off southpaws. 

The White Sox won’t see a ton of lefties against the Astros, at least when it comes to starting pitching, but Houston has a few lefties in the bullpen, including star closer Josh Hader. And if Chicago advances to the ALDS against Cleveland, the Guardians have a number of different southpaws that Grichuk would be tasked with matching up against. 

Under-the-radar National League X-factors for the 2026 MLB playoffs

From key bullpen arms to overlooked bats, these six players could become some of the most important names in the National League postseason.

Milwaukee Brewers: 1B Jake Bauers

The Brewers’ style of play has not translated to October just yet, but they are better equipped for a run this year due to more slug in the lineup. Bauers is a big part of that.

The veteran first baseman has had a fantastic year for Milwaukee. He leads the squad with 26 home runs, and the lefty hitter is not someone who needs to be platooned. Bauers is OPSing over .900 off southpaws in 2026, hitting eight homers off them. That’s huge as it makes it a lot harder for opposing managers to utilize their bullpen when a lefty slugger holds his own off lefty relievers. 

The Brewers managed only four runs in the NLCS last year, but Bauers gives them the chance to score a lot more runs should he carry over his great – and consistent – play into October. 

Los Angeles Dodgers: RP Edwin Diaz 

The Dodgers dished out big money to add Diaz, arguably baseball’s best closer over the last decade, to the back of their bullpen. Injuries have largely derailed Diaz’s first year in Los Angeles, as he’s appeared in only 22 games. That, plus inconsistent results, have resulted in Diaz not being the team’s closer. Tanner Scott will serve in the ninth inning in October. 

But Diaz has been great this month since returning from injury, pitching five scoreless innings with eight strikeouts and no walks. If he’s back in form, he can be a major weapon for the Dodgers in key spots, especially with Blake Treinen out for the postseason with a shoulder injury. This is what L.A. brought Diaz in for – to get key outs in October. 

Atlanta Braves: SP Tyler Mahle

What a year it has been for Mahle. He pitched to a 5.13 ERA for San Francisco before being sent to Atlanta in what wound up being one of the best trades of the summer for a contender. 

Mahle has been excellent for the Braves. In nine games, he’s 4-1 with a 1.99 ERA and a sub-1 WHIP. Everything has seemed to click. He’s given up more than two runs in just one start since the trade, though that was his last start of 2026.

Mahle will pitch Game 2 for the Braves against the Phillies, pitching after ace Chris Sale. That means Mahle is pitching a game that either he has to win to keep the Braves’ season alive, or one that could send Atlanta to the NLDS for a date with the Dodgers. That will be Mahle’s first career playoff appearance in his 10th season. 

San Diego Padres: RP Adrian Morejon 

If the Padres are going to make a run, their pitching will be key. They have the best back-end bullpen in the postseason with Mason Miller closing, and Morejon is as good of a lefty reliever as you’re going to find. 

The eighth-year southpaw pitched yet another sub-3 ERA season in 2026. His strikeout numbers are up, and he’s still elite at preventing home runs. And that he’s a lefty in particular will be critical, especially for the Wild Card Round against Chicago and likely NL MVP Pete Crow-Armstrong. Plus, Morejon has worked multiple innings a lot in his career, which is a big boost for the Padres.

Morejon is just 27 years old, but he’s set to hit free agency this offseason. He will have a great market regardless, but a strong October showing sure won’t hurt. 

Chicago Cubs: SP Kevin Gausman

The Cubs needed rotation help in a big way this season, so they traded for Clay Holmes and Gausman. I think of the two, Gausman is more important. 

Gausman is a veteran arm who, at his best, has been a Cy Young-caliber pitcher in recent years for Toronto. He’s had a down year by his lofty standards – especially since the trade – but the right-hander is a proven vet who has pitched well in big spots.

Gausman had a 2.93 ERA in five starts and a bullpen appearance in the Blue Jays’ World Series run last year. He also pitched very well in his one 2022 playoff start before the bullpen blew a big lead to Seattle. Gausman has appeared in 14 playoff games in total as well.

It looks like Gausman will pitch Game 1 or 2 for Chicago in the Wild Card Round, and that’s exactly why they brought Gausman over from Toronto. If he can turn back the clock a bit after a rocky year, that would go a long way in the Cubs’ World Series aspirations. 

Philadelphia Phillies: IF Alec Bohm 

The Phillies won on Sunday, avoiding a major stumble at the finish line to get into the postseason. This is a team with a ton of postseason experience as well as an elite rotation, so there are a lot of good names to choose from.

I think Bohm will be a key factor for the Phillies in October. He’ll be plenty motivated given he’s a pending free agent who has not always been at his best in the playoffs, but Bohm also enters the postseason in good form. He shook off a really bad start to 2026 with an OPS of nearly .800 in the second half. 

Bohm makes a lot of contact and provides some thump, and with some hitters in this lineup being strikeout-prone, you need quality at-bats from other guys. That’s where Bohm thrives, and I think he can come up big for Philly here.