MINNEAPOLIS -- The Twins finally have one of their relievers healthy again -- but another one took his place on the injured list.

Minnesota reinstated right-hander Zack Littell from the 10-day IL on Thursday following his recovery from a left hamstring strain that had sidelined him since Aug. 1. The bullpen still isn't whole, though, as rookie Cody Stashak was sent to the IL with lower back inflammation, retroactive to Wednesday.

The Twins also designated veteran right-hander Cory Gearrin for assignment or release in order to make room on the 28-man roster for versatile infielder Ildemaro Vargas, who was acquired Tuesday in a trade with the D-backs.

Littell's return to the bullpen offers the Twins another arm to bridge the gap in the middle innings with the potential for multiple-inning stints. The 24-year-old broke out with a 2.68 ERA in 37 innings of relief last season following his conversion from starting to a bullpen role. He allowed four earned runs over three innings in his first two appearances of the season before his injury.

Stashak is a tough loss for the Twins, as the 26-year-old had continued to impress with a 3.86 ERA and 10 strikeouts in seven innings in 2020 after he carved out a bullpen role toward the end of last season.

Twins manager Rocco Baldelli and pitching coach Wes Johnson appeared to have grown more comfortable using Stashak in higher-leverage situations to protect slim leads and tie games in the middle-to-late innings, giving the club additional reliable depth alongside Taylor Rogers, Sergio Romo, Tyler Duffey, Trevor May and Tyler Clippard in such situations. Stashak threw an impressive inning in Tuesday's bullpen game in Milwaukee, striking out the side on 12 pitches.

Baldelli and president of baseball operations Derek Falvey said Stashak had been pitching through the tightness and soreness in his back for some time, which limited his ability to pitch on back-to-back days or for multiple innings. The Twins are hoping to get ahead of the injury by getting Stashak off his feet before the issues increase in severity.

"It was really hard for him every day to get that thing loose, and it has been something he’s been battling through throughout the year so far," Baldelli said. "Exactly when it popped up, I’m not exactly sure when the moment was, or the first day. I couldn’t tell you right now, but it’s something that has kind of been a chronic thing for him early this year, and something that we think with some rest we can just wipe out."

Gearrin made one appearance for the Twins, throwing two hitless innings in Kansas City on Sunday. The 34-year-old had been signed to a Minor League contract during the offseason before the Twins selected his contract to the active roster Sunday as additional bullpen depth towards the end of a stretch of 16 consecutive games.

Vargas' addition to the roster in Gearrin's stead means the Twins have some more flexibility with a four-man bench, and Marwin Gonzalez and Ehire Adrianza could be less heavily used in the continued injury absence of Josh Donaldson. The 28-man roster how has 15 pitchers and 13 position players. Baldelli expects to use Vargas primarily at second base, third base and shortstop. The 28-man roster how has 15 pitchers and 13 position players.

"One thing I want to add is probably hitting for more power," Vargas said. "Eventually to keep developing power and get stronger hits."

Hill likely to pitch next week
Rich Hill threw a 60-pitch bullpen session at the Twins' alternate training site in St. Paul, Minn., on Friday morning and "felt great," according to Falvey. The Twins hope to slot him in for a return to the rotation during this homestand, likely toward the middle of the coming week. With four days' rest, Hill could return as soon as Wednesday's game against the Brewers.

"Everything went great over in St. Paul," Baldelli said. "Physically, he feels really good; mentally he’s in a good spot, so I think we can have him built up where he can make a start this week for us. ... It’s very encouraging. It also gives everyone coming in after him potentially an extra day, which is also nice in this 20-game stretch as well."