Keirsey (oblique) began a rehab assignment Tuesday with the Twins' rookie-level Florida Complex League affiliate and went 1-for-3 with two runs in his first game with the team.
Keirsey has been on the 7-day injured list at High-A Cedar Rapids since Aug. 12 with a right oblique strain. He's not expected to require more than a handful of games in the FCL to get his timing back at the plate before he rejoins Cedar Rapids.