When it comes to postseason baseball, there are few things more valuable than a strong bullpen.

Don’t believe us? Just take a look at last year’s Houston Astros, who won the 2022 World Series thanks in part to a dominant bullpen that became the first bullpen in MLB history to throw at least 40 innings in a single postseason and post a sub-1.00 ERA. Seven Astros relievers made multiple appearances during that playoff run, and none had an ERA above 2.00.

With that dominance in mind, here’s a look at 10 bullpen weapons who could end up playing important roles this October.

Note: all stats are through Friday's games

Bryan Abreu, RHP, Astros
Stats: 67 1/3 IP, 1.87 ERA, 1.04 WHIP, 4 SV

Abreu might be the best pitcher in baseball that no one’s talking about. After finishing last season with a 1.94 ERA in 60 1/3 innings, Abreu put together 11 1/3 scoreless innings for the Astros in the postseason on their march to a World Series title. He’s been even better this year thanks to a nasty slider (.161 batting average against) and four-seam fastball (.182). He hasn’t allowed an earned run in two months and has become the perfect eighth-inning bridge to closer Ryan Pressly, for an Astros team looking to become the first repeat champions since the 2000 Yankees.

Shawn Armstong, RHP Rays
Stats: 49 2/3 IP, 1.09 ERA, 0.81 WHIP

There’s dominant pitching, and then there’s Armstrong’s 2023 campaign. His WHIP is minuscule (0.81, which is second in baseball among pitchers with 40 innings). His walk rate is incredible (1.6 BB/9, which is 16th in baseball). His xWOBA is sparkling (.243, which is third in baseball among pitchers with 100 batting ball events). Last May, Armstrong had a career ERA near 5.00 and was designated for assignment by the Marlins. Now he’s arguably the most important arm in one of baseball’s best bullpens.

Aroldis Chapman, LHP, Rangers
Stats: 56 2/3 IP, 2.86 ERA, 1.21 WHIP, 5 SV

The Rangers made the first big move of Trade Deadline season by acquiring Chapman at the end of June. After dominating in his first month with the Rangers (1.69 ERA in his first 16 appearances) he has run into trouble recently for a Texas bullpen that has a 5.03 ERA (seventh-worst in baseball) since Aug. 1. While Chapman ranks in the 99th percentile in expected batting average and ERA, he’s allowed a run in five of his nine appearances. If the Rangers make it to October, they’ll need the best version of Chapman to return.

Caleb Ferguson, LHP, Dodgers
Stats: 57 1/3 IP, 2.51 ERA, 1.36 WHIP, 3 SV

There’s no telling what the Dodgers’ pitching situation will look like come October, thanks to a rotation filled with question marks. All that uncertainty could lead to a lot of work falling on the shoulders of the Ferguson and the rest of the Dodgers’ bullpen. He’s been a reliable seventh and eighth inning guy for manager Dave Roberts this season, but has also served as an opener at times, which is where he could make his impact in the postseason ahead of rookie Ryan Pepiot.

Kevin Ginkel, RHP, D-backs
Stats: 62 2/3 IP, 2.15 ERA, 0.91 WHIP, 4 SV

A longtime D-back, Ginkel's finally living up the promise he showed in his 25-game cameo in 2019 (1.48 ERA in 24 1/3 IP). After posting ERAs above 6.0 in 2020 and '21, he was outrighted off Arizona's 40-man roster ahead of the '22 season. He impressed after a call-up last August and has looked like a new pitcher this season thanks to a strong fastball (.211 opponent batting average against) and wipeout slider (38.8% whiff rate). With Paul Sewald holding down the ninth inning, Ginkel has emerged as manager Torey Lovullo's go-to eighth inning arm.

Craig Kimbrel, RHP, Phillies
Stats: 66 IP, 3.27 ERA, 1.07 WHIP, 23 SV

While Kimbrel picked up a World Series ring in 2018, he has a 4.13 ERA in 24 career postseason innings, and was struggling so much at the end of last season with the Dodgers that Roberts left him off the team’s NLDS roster. He’s looked like a new pitcher this season with the Phillies, however, posting a 2.25 ERA since he became the team’s closer when José Alvarado got hurt at the beginning of May. Last postseason, five different players picked up saves for the Phillies on their run to the World Series; this year, manager Rob Thomson is hoping all of those opportunities will be gobbled up by Kimbrel.

Emilio Pagán, RHP, Twins
Stats: 65 1/3 IP, 3.17 ERA, 0.98 WHIP

Another graduate of the Rays pitching factory, Pagán is putting together his best season since he was a stellar back-end piece for Tampa Bay in 2019. The biggest reason for his turnaround has been the resurgence of his cutter, which has held hitters to a .139 batting average this year compared to a .326 last season. He leads the Twins in innings pitched out of the bullpen, and could end up being the first reliever manager Rocco Baldelli calls upon if a starter runs into trouble early.

Cionel Pérez, RHP, Orioles
Stats: 51 1/3 IP, 3.68 ERA, 1.51 WHIP, 2 SV

In 2022, Pérez was a breakout star for the Orioles, tallying a 1.40 ERA in 57 2/3 innings after entering the year with a career ERA over 6.00. But he failed to carry that momentum into the beginning of this year, as he had an ERA above 4.00 in each of the first four months, and ended play on July 27 at 4.81 after allowing a run against the Phillies. 

But then something clicked, as Pérez tossed 17 2/3 scoreless innings in the two months after that outing before allowing three earned runs against the Guardians on Sept. 21. If the Orioles make any kind of postseason run, Pérez will likely end up playing a big part in it, as closer Félix Bautista could potentially miss the postseason with a UCL tear.

Michael Tonkin, RHP, Braves
Stats: 77 IP, 4.09 ERA, 1.05 WHIP

Last year, the Braves got a combined 7 2/3 innings out of their starters in their three NLDS losses to the Phillies, which led to Atlanta’s bullpen being called upon early and often. That’s where Tonkin comes in this year, as the 33-year-old has gone multiple innings in 29 of his 43 appearances, five of which have been appearances of three innings or more. That said, he’s struggled as of late and has allowed at least one run in his last five appearances, so the Braves will need him to turn things around quickly.

Abner Uribe, RHP, Brewers
Stats: 28 IP, 1.29 ERA, 1.07 WHIP

Uribe boasts an electric fastball to go along with his 80-grade name. The hard-throwing rookie already holds one Brewers record after he unleashed a 102.2 mph fastball earlier this season, and now has his eye set on postseason glory. Uribe’s allowed two earned runs over his last 22 appearances, and has been holding batters to a .150 average with his sinker.