FORT MYERS, FLA. – The Twins might have lost a member of the starting rotation for the entire year, and they'll be without two key members of their bullpen, including closer Jhoan Duran, to begin the upcoming season.

Anthony DeSclafani was shut down because of elbow soreness after pitching in a minor league game Saturday and he will visit Dr. Keith Meister to evaluate his next steps, which could include elbow surgery, Twins President of Baseball Operations Derek Falvey said Monday.

Duran is sidelined because of a moderate right oblique strain, which occurred when he was warming up to throw a live batting practice session Sunday, and he will be placed on the 15-day injured list. Caleb Thielbar, who has yet to pitch in a Grapefruit League game, continues to be slowed because of left hamstring soreness and will begin the season on the IL.

Falvey didn't announce a timeline for Duran to return, but the Twins are bracing for the possibility of losing their closer for the next month.

"When Jhoan Duran goes down," Falvey said, "that's a tough loss, no question."

The pitching injuries will be an immediate test of the Twins' pitching depth. Louie Varland is expected to fill the final spot in the starting rotation, joining Pablo López, Joe Ryan, Bailey Ober and Chris Paddack. Varland hasn't permitted a run in 11 innings this spring, totaling 11 strikeouts and one walk.

Falvey didn't rule out attempting to add a starter for additional depth, but he said he was encouraged by the way Class AAA starters Simeon Woods Richardson, Brent Headrick and David Festa looked during camp.

"No such thing as too much pitching depth," Falvey said. "We're going to need it."

DeSclafani pitched 1â…” innings in a Class AAA minor league spring training game Saturday. He reached 94 mph with his fastball, which is his typical velocity, but he felt soreness after his outing.

There was obvious injury risk in acquiring DeSclafani from Seattle as one of the four players acquired in the Jorge Polanco trade. DeSclafani missed the final two months of last season because of a right elbow flexor strain, and there was a previous stint on the injured list because of right shoulder fatigue. He was traded twice this winter with the Twins on the hook for only $4 million in his $12 million salary.

"I wish we could say every pitcher has a perfectly clean situation," Falvey said. "This is one where he dealt with it before, he rehabbed it, he was in a good place. All the medical stuff we had and everything around the offseason … we knew there was a risk to this going forward. Ultimately, [it's] just something that has cropped itself up."

Duran's absence means Griffin Jax and Brock Stewart are the top candidates to serve as the Twins' closer for at least the first few weeks of the 2024 season. Duran felt a cramp in his right side during his warmup pitches Sunday, and he underwent a magnetic resonance imaging exam Monday. The Twins plan to reevaluate him in a week.

"The same guys that were pitching late-inning situations for us like Griffin and Brock, those guys will continue to pitch late-inning situations for us," Twins manager Rocco Baldelli said. "The games themselves will dictate who pitches when, but I'm not going to sit here and tell you that this guy is going to end up pitching this inning because that's not how I like to think about the game."

Thielbar felt tightness in his hamstring during his 20-pitch live batting practice session Saturday. He will be shut down from pitching until his hamstring heals. Without Thielbar, the Twins will likely lean on Steven Okert, acquired from Miami in a trade for utilityman Nick Gordon, and Kody Funderburk as their lefty relief options.

Righty reliever Zack Weiss, an offseason waiver claim, has yet to pitch in a Grapefruit League game because of a right teres major strain (on the backside of the upper arm) earlier in camp. He will start the season on the 15-day IL, but he has begun throwing and could start a Class AAA rehab assignment around Opening Day.