Boyd (triceps) will begin a rehab assignment with Triple-A Toledo on Thursday, Evan Petzold of the Detroit Free Press reports.
Boyd has been out for nearly two months with triceps tendinitis. Given the length of his absence, he'll presumably require multiple rehab appearances before he returns from the injured list. If he makes three rehab starts, he could return sometime in late August, though the Tigers have yet to specify exactly when they expect him back.