De Leon will be a part of the Reds' 60-man player pool this season.
He is on the 40-man roster but will not be among the group training at Great American Ball Park. De Leon spent the majority of 2019 pitching at Triple-A as a member of the Rays organization, logging a 3.51 ERA, 1.32 WHIP and 73:27 K:BB in 51.1 innings.