Diekman (abdomen) threw eight light tosses off a mound Monday, T.R. Sullivan of MLB.com reports.
Diekman is preparing to throw a second, more intense bullpen session Thursday, so Monday's workout was just a means of familiarizing himself with the slope of the mound after having not toed the rubber since October. The lefty, who underwent his third and final surgery June 9 to address ulcerative colitis, has been able to keep his arm conditioned by throwing off flat ground for the last month. Prior to doing the light tosses off the mound, Diekman stretched his flat-ground distance out to 170 feet Monday, according to Evan Grant of The Dallas Morning News. Diekman remains without an official timetable for a return from the 60-day disabled list, but mid-to-late August seems like a reasonable estimate.