Swarzak battled those symptoms during his spot start against the Tigers on Friday, when he allowed six runs on nine hits over 3 2/3 innings.
He was moved back to the bullpen after that outing, and is expected to be ready to pitch in long relief by Monday or Tuesday.
"We'll have Swarzy back here in a day or so," manager Ron Gardenhire said. "We'll have some flexibility."
Swarzak has fared well as a reliever, posting a 3.06 ERA in 17 2/3 innings, but he has struggled as a starter, with an 8.34 ERA in 18 1/3 innings.