De Leon will make his Triple-A Oklahoma City debut Tuesday as he returns from a minor ankle injury, J.P. Hoornstra of the Southern California News Group reports.
De Leon split time between Double-A Tulsa and High-A Rancho Cucamonga last season and finished the season with a 2.99 ERA and .208 opponent batting average. Oklahoma City will hope he comes out strong, as the lowest ERA among their regular starters is 3.86.