De Leon will serve as the Twins' opening pitcher in a bullpen game Saturday versus the Tigers, John Shipley of the St. Paul Pioneer Press reports.
De Leon will likely pitch an inning or two before turning the game over to the rest of the Twins' relief corps. The right-hander has been a productive member of the bullpen since coming up from Triple-A St. Paul in mid-May, logging a 3.86 ERA and 15:4 K:BB in 14 innings.