De Leon (elbow) will begin a minor-league rehab assignment at High-A Charlotte on Saturday, Josh Tolentino of The Athletic reports.
De Leon has been throwing in extended spring games for the past few weeks, and he continues his return from Tommy John surgery last spring. The 26-year-old will be eligible to be activated off the 60-day injured list in late May, but it's not fully clear when he's expected to be ready for his return.