The Twins options pitcher Michael Tonkin to Rochester after he gave up a run in one inning on Friday.
Tonkin had a 6.75 ERA for the Twins this spring.
"He needs to become more efficient with his secondary pitches," manager Paul Molitor said, per MLB.com's Rhett Bollinger. "It seems to me he gets into trouble because people are looking for that fastball pretty much. They're going to get one at some point, so that secondary pitch has to get better to not just get ahead but to finish. He's got enough life on his fastball, but it gets a little predictable at times."