Hearn's throwing program was shut down due to elbow irritation Monday, Evan Grant of The Dallas Morning News reports.
Hearn recorded a single big-league out before landing on the injured list with elbow tightness in late April. He resumed throwing in July before the issue popped up again. The renewed irritation reportedly isn't related to his UCL, so Tommy John surgery isn't expected to be required, but he may not have time to build up the arm strength to pitch again this season.