4 candidates Phillies should consider calling-up to help the big league bullpen

After a rough start to the season for some Phillies relievers, some pitchers within the system are making their case for a call-up.
ByJake Huber|
Boston Red Sox v Philadelphia Phillies
Boston Red Sox v Philadelphia Phillies | Julio Aguilar/GettyImages

Through 21 games, heading in to Sunday's series finale with the Miami Marlins, the Philadelphia Phillies had the third-worst bullpen ERA in MLB at 5.54. After a few years of bliss, the 2025 Phillies are creeping backward into the rubble and giving fans flashbacks of Joe Girardi-era bullpens.

The ending of the team's 2024 postseason run and the departure of two of their top relievers in Jeff Hoffman and Carlos Estévez during the offseason left the arm barn battered and torn, but not devastated. Returning top relievers like 2024 All-Star Matt Strahm, José Alvarado and Orion Kerkering have all started off the season on a good note, allowing only five runs combined over 24 2/3 innings.

On the other hand, other players have struggled mightily. Between Carlos Hernández, Joe Ross, José Ruiz and Jordan Romano, 33 earned runs have crossed the plate and 16 batters have been put on base with a free pass. While Romano looked great in three outings following a mechanical adjustment, Saturday's implosion set him back again.

4 candidates Phillies should consider calling-up to help the big league bullpen

It's likely too early for a major move by the team, but the Phillies have several candidates who could bring a different skill set and fill a role instantly in the bullpen. Here are four minor league arms who the front office should consider calling on if the major league bullpen's struggles continue.

Koyo Aoyagi, RHP

A former Nippon Professional Baseball (NPB) league veteran playing his first season stateside, Koyo Aoyagi has settled in after struggling in his first spring training.

The 31-year-old spent nine seasons in Japan playing for Hanshin Tigers pitching to a 3.08 ERA in 214 games. During his spring training outings, the Yokohama native looked visibly shaken and uncomfortable and ultimately pitched poorly, allowing four runs in three innings. When the calendar flipped to baseball that counted, though, the sidearmer has been great.

Over seven innings in 2025 for the Triple-A Lehigh Valley IronPigs, Aoyagi has allowed only one run while striking out eight hitters. While he has struggled a bit with command, walking five batters and hitting two, he has more top-level professional experience than anyone in the minor league system by far and his funky delivery could lead to an effective rookie campaign.

Joel Kuhnel, RHP

Another pitcher with major league experience, right-hander Joel Kuhnel has been great with Lehigh Valley to begin 2025 after spending time with Tampa Bay, Houston and Cincinnati during his 11-year career.

Through 9 1/3 innings, the North Carolina native has pitched to a 1.93 ERA and has walked only one hitter while striking out 10. Kuhnel throws a ton of strikes while limiting walks, with just a 5.9 percent rate in his 93 2 /3 MLB innings. His five-pitch mix, which includes a sinker that has reached upwards of 100 mph earlier in his career, gives him an edge against most relievers with the ability to mix and match and change patterns.

The Phillies would have to clear a 40-man roster spot for Kuhnel, which brings a bit more fog on his way to the majors once again. But his prior experience and exceptional start to the season could convince the front office to give him a shot.

Devin Sweet, RHP

Former Seattle Mariner and Athletics reliever Devin Sweet has a very likable pedigree, pitches a lot, and strikes out a lot of hitters.

Before being acquired from the Tigers, the small-righty flexed his stuff for Triple-A Toledo, striking out 111 batters in 76 innings. Much like most fringe MLB bullpen arms however, command has been the problem, as he boasts a 4.4 BB/9 across his time in Triple-A. He has a 1.35 ERA and 1.05 WHIP in 6 2/3 Triple-A innings so far this season, but has once against struggled with command, issuing four walks with four strikeouts.

Sweet's stuff is undeniable, but at times it's hard for him to be around the zone, which isn't necessarily what the major league team would be looking for as a last arm out of the pen. His ability to pitch multiple innings would give manager Rob Thomson more flexibility — he pitched those 76 innings last season in only 52 games. Sweet's a real Swiss-army knife who could eat innings and provide quality relief.

Max Lazar, RHP

Max Lazar, 25, debuted last season with the Phillies and showed flashes of MLB-caliber pitching, posting an ERA of 4.61 in 13 2/3 innings. Starting 2025 with the IronPigs, he has allowed only three earned runs in eight innings for a 3.38 ERA with a 0.88 WHIP.

The Florida native finds himself as one of the long shot candidates due to his experience with the major league team and his position within the organization — he's one of the last relievers left on the 40-man roster not already with the team. Lazar has a traditional four-pitch mix and the ability to stretch across multiple innings.

If the Phillies are looking into minor league starters to fill a bullpen roll, others like Nabil Crismatt and Seth Johnson have outside shots at a call-up. Both have MLB experience, while Crismatt would need to find a 40-man spot, Johnson is on the 40-man roster and would be an easier call-up.

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