It’s no secret that bullpens can make or break a season. Just ask the 2020 Phillies. Despite having a solid lineup (108 wRC+) and excellent starting pitching (6.9 fWAR, third-most in baseball), Philadelphia missed the expanded playoffs by a game. How? A 7.06 ERA from their bullpen, that’s how.

But relief pitchers become even more important in the postseason, if teams are lucky enough to get there. Managers put starting pitchers on shorter leashes. Every matchup is scrutinized.

Every contender could use at least one or two more bullpen arms. More may be moved, but here’s a look at seven relief pitchers who are expected to be available leading up to this year’s Trade Deadline. One of them could be the difference between vacation, a playoff berth or a World Series trophy.

All stats through Tuesday.

Joe Mantiply, (ARI)
Selling point: Neutralizes LHB

The 31-year-old left-hander has been the anchor for Arizona’s bullpen this year, posting a 2.37 ERA over 38 innings, striking out 38 while walking just two batters. Drafted in 2013 by the Tigers, Mantiply has bounced around a bit since then. But he’s come into his own in the Valley of the Sun by avoiding free passes and limiting hard-hit balls.

With his funky sidearm delivery, Mantiply owns left-handed batters. Lefties are hitting just .228 against him this season while striking out 31.1% of the time. If you’re a team that may face the likes of Yordan Alvarez, Freddie Freeman or Matt Olson this October, Mantiply might be your guy.

But not even right-handers are making great contact against Mantiply. His 1.9% barrel rate ranks in the 98th percentile in baseball. Mantiply is getting a ground ball on nearly 60 percent (59.3%) of his batted balls, which is more than 12 percentage points higher than last season.

Mantiply won’t be a free agent until after the 2026 season due to a late start to his career, so he could be around for more than just this year’s playoff run. He’s a worthwhile addition for those with a dearth of lefties in their bullpen.

David Robertson, Cubs
Selling point: Big-game experience

There’s nothing like October baseball. And Robertson has seen a ton of it.

Robertson has pitched in seven different postseasons. In 33 playoff games, he has a 3.11 ERA, including a 5-0 record. Robertson will be remembered for his playoff runs with the Yankees, but he even pitched four scoreless innings during the Rays' playoff run last season. Only four active pitchers (Kenley Jansen, Joe Kelly, Clayton Kershaw and Aroldis Chapman) have pitched in more playoff games than Robertson.

Oh, and he hasn’t pitched too badly this season, either. Robertson has a 1.83 ERA in 39 1/3 innings and 14 saves serving as the Cubs closer for the majority of this season. And that earned run average is no fluke. His expected BA, expected SLG and xwOBA all rank in the 90th percentile or higher this season. It’s his best season since 2017, when he split time between the Yankees and White Sox.

Michael Fulmer (DET)
Selling point: Possible multi-inning ace, a la Josh Hader

From Andrew Miller to Hader, multi-inning relievers have taken October by storm in recent years. If anyone on this year’s trade market could be the next one, it’s Fulmer.

A starter as recently as last season, Fulmer made the transition to the bullpen full time this season. And he’s been completely dominant. Fulmer has a 2.92 ERA, giving up just one home run in 37 innings. Hard contact has been nearly nonexistent against Fulmer. He’s given up just one barrel in 99 batted ball events.

While he hasn’t pitched more than 1 2/3 innings in an outing this season, Fulmer's former life as a starter suggests he could stretch out during the postseason. He pitched at least three innings in four appearances as recently as April 2021.

Fulmer should be worth the price tag if he goes just one inning at a time. But the possibility of being a bridge between your starter and closer or an extra-inning ace should entice teams even more. With the Tigers rumored to be sellers, expect them to move Fulmer to a contender this week.

Jorge López (BAL)
Selling point: Ground-ball machine

There might not be a story more incredible than López’s season. After posting an ERA north of 6.00 in three consecutive seasons, López made the American League All-Star Team this season as the Orioles’ lockdown closer.

Like Fulmer, López has looked like a new pitcher out of the bullpen after trying his hand at starting for years. López’s 1.55 ERA is the fifth lowest among relievers with at least 40 innings pitched this season. He’s posted a 0.93 WHIP – Lopez had never had a WHIP below 1.47 coming into this season.

He’s throwing his heater more than two ticks faster, getting a ton of ground balls and avoiding the long ball, all while striking out more than 10 batters per nine innings pitched.

There’s one big problem with López’s trade candidacy: The Orioles may not be looking to sell at all. López has been, perhaps, the best arm in an improved Baltimore bullpen. The Orioles might need to be blown away by an offer. But if they do opt to build for next year and beyond, lots of teams could use an arm like his.

David Bednar (PIT)
Selling point: Potential top-shelf closer

Bednar could very well be the best reliever on the trade market. The hard-throwing right-hander has a whopping 61 strikeouts in 45 2/3 innings this season. He’s going on two years of dominance now. Last year, Bednar finished in the top 15 among relief pitchers in both ERA (2.23) and strikeouts per nine innings (11.42).

Though his fastball tops out at around 98 mph, it’s his secondary pitches — a curveball and split-finger — that drive his excellence. Batters are hitting just .162 with only three extra-base hits in 74 at-bats against Bednar’s curve and split combined this season.

Bednar isn’t a free agent until 2027, so any trade for him will require a haul. But the Pirates aren’t close to being a contender yet. Perhaps they can find their next Oneil Cruz by trading another bullpen ace.

Daniel Bard (COL)
Selling point: Experienced, hard-throwing sinker-baller

First-round Draft pick. Dominant reliever. The yips. Retirement. Comeback Player of the Year. Bard’s career has had more twists and turns than a Jordan Peele movie. Now, he may be the missing piece for the next World Series champion.

Well out of the National League West and Wild Card race, the Rockies are expected to move Bard, who is enjoying one of the best seasons of his unbelievable career. At 37 years old, Bard’s 1.91 ERA would be a career low. The right-hander still walks quite a few batters (12.2% walk rate), but his expected batting average (.169) ranks in the 98th percentile in all of baseball.

And he’s done it all while pitching at Coors Field. Bard has given up just two home runs in 21 innings in Denver this season, holding batters to a .164 average. It might be impossible to improve on those numbers, but there isn’t a ballpark in Major League Baseball that’s less friendly to pitchers.

Bard is only signed through this season, so it might not take much to pry him away from Colorado. He’s only pitched in two postseason games — way back in 2009 — but Bard would come with more than enough life experience to handle the big stage.

Carl Edwards Jr. (WAS)
Selling point: Induces weak contact

The Nationals figure to be busy at the Trade Deadline. Even if they don’t move Juan Soto, Josh Bell is sitting there for the taking. They also have a bevy of bullpen arms who could help contenders, including Edwards.

The 2016 World Series champion with the Cubs has bounced around in recent years, playing for five teams since leaving Chicago in 2019.

After throwing just 27 1/3 innings over the last three seasons, Edwards has given the Nationals 36 2/3 innings of sub-3.00 ERA ball. He’s striking out nearly nine batters per nine innings, but Edwards' success has derived from his ability to induce weak contact. His barrel rate, hard-hit rate and average exit velocity allowed all rank in the 87th percentile or better this season.

Edwards may be tired of bouncing around, but it’s the only way he’ll get back to the postseason anytime soon. The 30-year-old right-hander will look to bring back some of that curse-breaking magic wherever he goes next.