Sean Marshall has been sidetracked in his return from a shoulder injury. The southpaw has been sidelined since late May with a sprained left shoulder and currently resides on the 60-day disabled list. Marshall was set to head out on a rehab assignment after the All-Star break, but he felt pain in his shoulder during a batting practice session. "We don't think it's consistent with his original injury," pitching coach Bryan Price said. "It's more of a tweak. He can't progress if he's feeling soreness. I think he's still strong. Hopefully, he'll be able to start his throwing program soon, so he doesn't fall out of throwing shape."