Opening Day is just over a week away. The Minnesota Twins will head to Kansas City with an injured bullpen. Twins President of Baseball Operations Derek Falvey announced that two of the bullpen’s top arms, Jhoan Duran (oblique) and Caleb Thielbar (hamstring), will start the season on the injured list.
While it doesn’t initially look like either pitcher will miss a significant amount of time, the Twins will need to fill two of the biggest roles in their bullpen. Duran evolved from a hard-throwing starting pitching prospect to one of the best closers in baseball. He has a 2.15 ERA in 130 innings throughout his career.
It will be the first time Duran has been on the injured list in his first two major-league seasons. Thielbar has been one of the team’s biggest bullpen development stories, recording a 3.21 ERA over 174 innings since returning to the Twins in 2020. His status as the go-to lefty opens a hole in Minnesota’s relief options.
The Twins recorded a 3.76 bullpen ERA that ranked 15th in baseball. However, most of that production came from top-end guys like Duran, Thielbar, and Griffin Jax, who they used regularly in high-leverage situations. Injuries like these would have devastated Minnesota’s bullpen a year ago when the unit was much more of a high-ceiling, low-floor group. But this season, the Twins bullpen is in a much better position to overcome the early-season injuries.
Replacing Duran will be the most difficult. With an average of 101.3 MPH on his fastball, Duran’s top-percentile velocity makes him one of the best strikeout pitchers in the league. The Twins don’t have another Duran-type closer, but Jax and Brock Stewart are capable replacements.
Jax or Stewart may not be ready to take on the full-time closer role, but the Twins haven’t always had a closer under Rocco Baldelli. They used a closer-by-committee early in 2019 before Baldelli officially gave the role to Taylor Rogers.
Duran wasn’t a full-time closer when the Twins first called him up. He had a 1.86 ERA through 67.2 innings pitched in 2022, but he only recorded 8 saves before earning the official closer title in 2023. Without another pitcher of Duran’s caliber, Rocco might go back to playing matchups in the ninth inning instead of pigeonholing another reliever as the closer.
Jax was more effective than his 3.86 ERA suggests a year ago when you see his 3.22 FIP and a 96.5 MPH average fastball velocity. More contact from Jax doesn’t mean he’s getting hit hard, though. His 86.8 MPH average exit velocity (88.4 MPH is league average) and career-low 33.3 percent hard-hit rate in 2023 show that he can generate weak contact against opposing lineups. Jax finished with a -0.19 win probability added (WPA) in 2023. But Jax had a 0.43 WPA from June 1 to the end of the season.
Stewart had the stuff to be a closer last year, with his 97.3 MPH average fastball velocity and a 35.8 percent strikeout clip. He could also keep the ball in the ballpark with a 0.33 HR/9 clip all last season. Overall, it led to a 0.96 WPA for the Twins in 2023. But Stewart’s injury history is a concern. He played in only 28 games last season and hasn’t pitched in a game since 2019. Stewart’s health could keep him from earning the job in Duran’s absence.
Filling the closer role with the committee of Jax and Stewart should be good enough to keep things calm until Duran returns, and Justin Topa could fill in as a setup guy. Coming over in the Jorge Polanco trade, Topa had his best season in 2023 with a career-best 2.61 ERA in 69 innings. Topa earned that 8th-inning setup man role in Seattle because of his 1.90 WPA last year.
You could make a case that Topa could join that closer committee and allow the Twins to play matchups while not riding one pitcher too often. Topa was great in high-leverage situations, but he only has had one breakout season and 3 career saves. Closers also typically have high strikeout numbers, and his 19.1 percent whiff rate and 21.9 percent strikeout rate a season ago won’t generate the swings and misses. That’s not to say he can’t be impactful as a closer, although teams like those high strikeout guys to slam the door. The ninth inning gets all the notoriety, but the Twins still need a capable guy to come in during other high-leverage situations in the late innings to make an impact.
One year ago, moving Stewart or Jax up meant putting a reliever that the team didn’t necessarily trust in high-leverage situations into a more prominent bullpen role. Josh Jackson and Josh Stamount are veterans with a proven track record in relief. They’re a step up from bullpen arms like Jorge Alcala, Emilio Pagan, or Dylan Floro. All three were occasionally serviceable, but none were steady enough to play a late-inning role.
Replacing Thielbar is challenging not just because of his production but also because he was also Minnesota’s primary left-handed relief pitcher. Jovani Moran couldn’t secure that second lefty spot in the pen, and now it’s wide open because Moran is injured.
The Twins acquired Steven Okert from the Miami Marlins in the Nick Gordon trade. Like Thielbar, Okert relies on his fastball and slider for a 29.6 percent strikeout clip despite his 93.8 MPH average fastball in 2023. A -0.4 WPA is workable in tight spots, even if it isn’t ideal.
Kody Funderburk has an extremely small sample size of 11 games against big-league hitters. One little bit of information from that small workload is that despite allowing a go-ahead home run in his MLB debut, Funderburk still finished his first big league season with a 0.41 WPA. Okert will likely be given the edge over Funderburk on Opening Day, and Funderburk has a chance to step right back into that mix.
There is a caveat to all of this. Bullpens can be flukey due to high-pressure situations and small sample sizes. But in a results-oriented position of relief pitching, fans don’t take much solace in bad luck. Two things can be true at once. The Twins can have a deeper bullpen than a season ago, but that doesn’t guarantee results. Especially considering that the Twins starting rotation likely won’t be top three in the AL in innings pitched. Still, it’s easier to bet on a team with more proven experience than a team that isn’t.
Duran’s absence will lower the ceiling of Minnesota’s bullpen. Whether it’s for two weeks or two months, losing Duran and Thielbar to start the season will mean new roles for relievers. However, the Twins spent most of the offseason raising the floor of their bullpen arms. If they need to cover for a short time, their relievers have the talent to hold down the bullpen until Duran and Thielbar can come back.
