The Minnesota Twins are placing right-hander Tyler Mahle on the 15-day injured list.
The move comes less than 24 hours after the hurler left a start against the Chicago White Sox with right shoulder inflammation.
Mahle had just returned after previously landing on the IL with a shoulder issue. The 27-year-old, who threw just 37 pitches Saturday against the White Sox, saw his average fastball velocity drop to 88.7 mph in the second inning.
"I wouldn't want to close the book on his season," Twins manager Rocco Baldelli said Sunday. "Is there an opportunity for him to come back and pitch? Maybe. But we have to learn a lot more before then."
Left-hander Jovani Moran, who Minnesota optioned to make room for Mahle's return, will take the hurler's spot on the roster.
The Twins acquired Mahle in a four-player deal with the Cincinnati Reds on Aug. 2. He owns a 1-1 record with a 4.41 ERA and 12 strikeouts across 16 1/3 innings (four starts) with the Twins.
Minnesota entered play Sunday with a 67-64 record. The Twins trail the Cleveland Guardians by one game for first place in the AL Central.