Leiter (ankle) will begin a rehab assignment at Triple-A Round Rock on Thursday, Shawn McFarland of The Dallas Morning News reports.
Thursday will mark Leiter's first taste of game action since he underwent surgery on his right ankle in June. He's expected to make multiple starts in the minors before returning from the injured list, and the plan is for him to throw about 40-to-45 pitches during his first outing.