Five Pirates Who Could Take Carmen Mlodzinski’s Bullpen Spot

The Pittsburgh Pirates are going to give Carmen Mlodzinski another crack at a starting rotation spot. While he faltered when given the opportunity to open 2025, Mlodzinski has more going for him this time. However, Mlodzinski served as a multi-inning reliever for most of 2025 and was slated to begin 2026 in a similar role. Now with a bullpen spot opened up, the Pirates have plenty of players whose chances of making the Opening Day roster just went up.

Who could make the Pirates’ bullpen with Mlodzinski in the rotation?

Evan Sisk

Evan Sisk was one of the many players the Pirates acquired at the trade deadline. Sent over from the Kansas City Royals (alongside Callan Moss) for Bailey Falter, Sisk had some decent numbers. The Southpaw pitched 17.2 innings for the Royals and Pirates, putting up a 3.56 ERA, 3.08 FIP, and 1.47 WHIP. Sisk was prone to free passes (12.5% BB rate), but had some quality peripherals.

Sisk nearly struck out a third of opponents with a 31.3% K rate. Additionally, he had an elite 31% whiff rate. Sisk also induced just an 87.1 MPH exit velocity and 4.7% barrel rate. That led to just one batted ball leaving the park. Despite sitting in the low-90s, Sisk had a 106 Stuff+. He is a low-arm-slot lefty at 16 degrees. Sisk’s extension off the mound was also in the 87th percentile, making his velocity play up.

The biggest argument against Sisk is that the Pirates already have two other lefty bullpen arms. They signed Gregory Soto earlier this offseason and acquired Mason Montgomery from the Tampa Bay Rays. He also has options remaining, so the Pirates can send him to Triple-A to open 2025 without running the risk of losing him. However, Sisk is an intriguing arm that has shown off quality stuff.

Brandan Bidois

After years marred by injuries, Brandan Bidois finally had his breakout year. Last season, Bidois had an astounding 0.74 ERA, 0.80 WHIP, and a 2.44 FIP. The Australian right-hander made appearances for Bradenton all the way up through Indy. Getting a strikeout 30% of the time with an 11.7% walk rate. However, the most impressive part of his season was not allowing a single home run.

Bidois throws mid-to-upper-90s with his four-seamer. Last year, he topped out at 98.1 MPH. He also has a slider that FanGraphs projects as a 70-grade pitch. His low-80s curveball is his second breaking pitch. Bidois also started utilizing the kick-change, a form of change-up where one finger is spiked into the ball to affect its spin axis. His kick-change sat in the low-90s last year.

He has legitimate high-leverage upside. The Pirates added him to the 40-man roster this winter to protect him from the Rule-Five draft. He may not be able to pitch multiple innings, like Hunter Barco, but he is the Pirates’ best relief pitching prospect right now. If the Pirates want a future set-up man (or even closer) instead of a multi-inning arm that could be a future starter, Bidois is the pitcher they will open the year with.

Kyle Nicolas

Kyle Nicolas has had a very rollercoaster Major League Baseball career. At times, he looks like a dominant reliever with elite stuff. At other times, he struggles to find the zone. 2025 was no different. By the end of June, Nicolas had multiple MLB stints and allowed ten earned runs in just 12 innings of work. He also walked more batters than he punched out, dishing out nine free passes to just eight strikeouts.

Nicolas was sent back to Indy in early June and wouldn’t reappear in MLB until the start of August. But things began to click for Nicolas down the stretch. Over his final 26 innings of 2025, Nicolas posted a 3.46 ERA, a 24.3% strikeout rate, and a walk rate of only 8.6%. He also only allowed one home run, with a barrel rate of 7.1%. His Stuff+ on the year sat at 106.

The only Pirates pitcher whose perceived four-seamer velocity outpaced Nicolas’ 98.8 MPH was Bubba Chandler. He also had the 25th-highest whiff rate among pitchers who threw a slider at least 100 times last year. Nicolas came in at an impressive 45.1%. If the Pirates opt to go with the reliever with the best stuff, Nicolas is a safe bet. He does have an option remaining, which will factor into whether he opens the year with the Pirates or not.

Yohan Ramirez

2025 marked Yohan Ramírez’s second stint with the Pirates. The right-hander pitched 33.1 innings out of the pen with a 5.40 ERA and 1.40 WHIP, but a solid 3.80 FIP. Ramirez’s 10.8% walk rate was poor, but many of his peripherals were still solid. He struck out 29.3% of opponents with a respectable 1.08 HR/9 ratio.

Ramirez’s underlying ERA estimators also liked his season. He owned a 3.34 SIERA and a 3.76 xFIP. There’s no question that Ramirez’s stuff is good. He sits 96-97 MPH with both his four-seam fastball and his sinker while having 94th percentile extension off the mound. That leads to a FanGraphs Stuff+ mark of 104.

Ramirez is out of options. If the Pirates want to send him to Triple-A at the end of Spring Training, that means they’ll have to expose him to waivers. That could give Ramirez an inside track to a roster spot. His underlying numbers are solid, and he has quality stuff. Control has always been a problem for Ramirez, but the Pirates could run him out as one of their low-leverage relievers until he proves otherwise, or another arm steps up.

Hunter Barco

Barco is not a reliever. He has spent most of his career as a starting pitcher. The left-hander made 23 starts and pitched 99.1 innings in the minor leagues last year. In that time, he put up a 2.81 ERA with a 3.54 FIP and 1.20 WHIP. He walked 11.8% of opponents, but had a healthy 27.8% strikeout percentage, and only allowed five homers. Barco’s performance between Altoona and Indianapolis earned him a late-season MLB cameo. He pitched three perfect innings with a trio of K’s during his brief look.

Barco is one of the Pirates’ top ten prospects. He even ranks among MLB Pipeline’s top 100. While he isn’t a flamethrower, sitting 92-94 MPH, he does throw from a low arm angle. Barco also has a mix of solid secondary offerings. His mid-80s splitter induced a 42.2% whiff rate at Triple-A. His upper-80s slider is the better secondary offering. However, it still had a strong 39% Triple-A whiff rate.

While Barco is a lefty pitcher with options remaining, like Sisk, he is in a different situation. Everyone else on this list is a single-inning reliever. However, Barco can fill the multi-inning role left behind by Mlodzinski, going to the rotation. If Mlodzinski struggles through the order a third time, Barco can help soak up some innings. Alternatively, if Mlodzinski struggles, Barco can take over his rotation spot.