Tyler Mahle threw 25 pitches in a bullpen session Friday, feeling good with all of his pitches since going on the injured list with a right shoulder injury. Mahle left his third start for the Twins on Aug. 18 in the third inning, citing arm fatigue. Initially, Twins manager Rocco Baldelli was optimistic it wouldn't lead to an IL stint.

But with the season dwindling and every roster spot precious, the Twins decided they couldn't quite go 10-plus days without another available arm and sacrificed Mahle for at least the required 15 days instead in order to call someone up from Class AAA.

Mahle is eligible to come off the IL in early September, amid the Twins' series at the White Sox, the team right behind them in third of the American League Central. Mahle's velocity averaged around 93 mph before this injury but dipped to sub-90 mph in that last start.

Baldelli said he's not sure whether Mahle's velocity has fully returned but did say the pitcher would continue to throw more bullpens with upped intensity before his return.

"He took some time off. I think it's allowed him to rest a little bit. It's allowed his shoulder to kind of recuperate a little bit and get him where he needs to be," Baldelli said. "So I think it will be time well spent. I would expect him to come back a different pitcher than his last start. I don't think that's unreasonable to think."

Injury progress

Two key field players are making promising steps toward their September returns.

Outfielder Trevor Larnach is set to go on a rehab assignment this week. The destination could be with one of the minor league teams in Florida, where Larnach has been working back at the Twins' facility in Fort Myers.

Larnach has been out since the end of June after having surgery on a core muscle injury. He had been hitting .231 before his departure with five home runs, 13 doubles and 18 RBI in 51 games.

Catcher Ryan Jeffers also threw for the first time Saturday, tossing a ball against a wall on the field pregame. Jeffers broke his right thumb and had surgery to reset the bone with some hardware. He hasn't played since July 14, and the team subsequently signed Sandy Leon to catch alongside Gary Sanchez while Jeffers recovers.

Jeffers will travel to Florida on Monday to continue his rehab, along with several other injured Twins players, including pitchers Bailey Ober (groin) and Kenta Maeda (Tommy John). All are eyeing returns before this season ends.