Leiter (hip) began a throwing progression Monday, MLB.com reports.
Leiter was placed on the injured list Saturday (retroactive to Thursday) due to a right hip impingement, but he didn't require much down time before resuming throwing. The Athletics are hopeful that the right-hander can return to the big-league club when first eligible July 3. In 29.2 innings this season, Leiter owns a 4.85 ERA, 1.38 WHIP and 31:10 K:BB with four saves.