"Aaron Harang, on the disabled list since June 13 with a stress fracture to his right foot, likely won't pitch until after the July 11-13 All-Star break.
"I'd say it's doubtful," manager Bud Black said.
Harang pitched off a mound for the first time Sunday since going on the DL.
"I had no discomfort," said the Patrick Henry High and San Diego State product.
Harang, who leads the club with seven wins (7-2, 3.71 ERA), has been fitted with a carbon-fiber insert in his right cleat. The insert is designed to prevent Harang's middle toe from flexing.
"It feels good," Harang said. "What it's going to come down to is testing the quick, explosive sprint to cover first or back up a base."
Harang said there's no timetable to test his foot with quick movements."