The Rangers selected Leiter's contract from Triple-A Round Rock on Thursday.
Leiter is set to start Thursday's game in Detroit in his MLB debut after posting a 3.77 ERA, 0.99 WHIP and 25:3 K:BB across 14.1 innings with Round Rock to begin the season. The Rangers are seemingly planning for Leiter to make just one start before heading back to the minors, but he could change minds if he pitches well, particularly with Andrew Heaney's struggles.