Farrell (jaw) will begin a rehab assignment with the Arizona Rookie League Rangers on Tuesday, T.R. Sullivan of MLB.com reports.
Farrell hasn't pitched in a live game since spring training, when he suffered a fractured jaw after being struck by a line drive. While it's good to see him back in action, his lengthy absence means he'll likely need a considerable amount of time in the minor leagues to get his arm back in shape. A timetable for his return has not yet been revealed.