Crowe has been absent from team workouts since they began July 3, Jesse Dougherty of The Washington Post reports.
Crowe is supposed to be training in Washington, as he was not listed on the roster sent to High-A Fredericksburg earlier this month. The 25-year-old struggled in Triple-A last season, posting a 6.17 ERA, 1.70 WHIP and 41:26 K:BB in 54 innings for Fresno.