PHILADELPHIA -- Milwaukee Brewers rookie left-handed pitcher Robert Gasser has gone on the 15-day injured list with a left flexor strain while left-hander Aaron Ashby and right-hander Tobias Myers were recalled from Triple-A Nashville.

The Brewers announced the moves Wednesday before their game at Philadelphia, where Ashby is set to start. They also optioned right-hander Janson Junk to Nashville.

Gasser had posted a 2-0 record and 2.57 ERA in five starts since making his major league debut last month. Gasser experienced tightness and soreness after his five-inning appearance Saturday in a 4-3, 10-inning victory over the Chicago White Sox. His assignment to the injured list is retroactive to Sunday.

His injury is the latest among the starters for the National League Central-leading Brewers, who already have Joe Ross (lower back), DL Hall (left knee) and Jakob Junis (right shoulder) on the injured list and Wade Miley (left elbow) out for the season. Brandon Woodruff, the Brewers' two-time All-Star right-hander, won't pitch at all this year as he recovers from shoulder surgery.

Ashby is coming back after spending the 2023 season out of the majors as he recovered from shoulder surgery, though he did make seven minor league appearances. In his lone outing with the Brewers this year, he gave up eight runs, four earned, over 3 innings in a 10-8 loss at Cincinnati on April 8. Ashby is 1-3 with a 6.80 ERA in 10 appearances for Nashville this season, but he has allowed just two runs over 12 innings in his past two starts.

Myers is back in the majors four days after getting sent down. He is 1-2 with a 5.40 ERA in seven appearances. Junk is 0-0 with a 9.00 ERA in three games with Milwaukee.