Rojas will serve as the opener for Tuesday's game against the Guardians, Dan Hayes of The Athletic reports.
Rojas most recently worked one inning Saturday against the Cubs, so he figures to work the first inning or so before giving way to a bulk reliever. The Twins cleared a spot on the big-league roster after Monday's game by optioning Woo-suk Go to Triple-A St. Paul, meaning the club will likely call up a fresh arm to work in relief of Rojas.