Leclerc was called up Tuesday, Evan Grant of the Dallas Morning News reports.
The 22-year-old has not yet stepped foot on a major league field, but will most likely do so with the crippled Rangers pitching staff needing fresh arms to get them to the All-Star break. Leclerc posted a 2.64 ERA over 44.1 innings between Double-A Frisco and Triple-A Round Rock this season.