PHOENIX -- The D-backs placed starter Trevor Cahill on the 15-day disabled list July 1 with a right hip contusion, but another issue has popped up since the right-hander began playing catch again last week.
"His shoulder didn't feel too good the last time he threw," D-backs manager Kirk Gibson said. "I don't have a timetable, we're just trying to keep him throwing on schedule, which he wasn't really able to do his last time. I have no idea why it happened, but I know it wasn't right."
Gibson added that Cahill was scheduled to throw again Monday before the club's series opener vs. the Dodgers to see if the discomfort went away.
After posting a 2.84 ERA in April and a 2.91 ERA in May, Cahill struggled in six June starts, going 0-5 with a 9.85 ERA.
The right-hander was hit on his right hip by a line drive on June 19, but said it was not a factor in his struggles.
Tyler Emerick is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.