The Pirates made the move Thursday and reinstated right-hander Jordan Lyles from the injured list.
Dickerson said the injury didn’t happen on any particular play and instead was something that had built up over time. He will be shut down from throwing for an indefinite amount of time, but will be able to swing and run while rehabilitating his shoulder and is not expected to require surgery.
The 30-year-old Dickerson hit .300 last season and won a Gold Glove in left field. He played in each of the Pirates’ first four games this season, going 2 for 13. He was not in the starting lineup Wednesday against St. Louis and grounded out as a pinch-hitter.
"It’s better to take care of it now and be able to help the team for as many months as I can at 100% than try to manipulate and let in linger and not help the team as much as I want," Dickerson said.
Pirates manager Clint Hurdle opted to keep an extra pitcher on the roster, in part because his bullpen allowed eight runs over seven innings and blew two saves in back-to-back losses to St. Louis. Additionally, Lyles, who had been dealing with right side discomfort, is scheduled to make his first start of the season Thursday night against Cincinnati. He hasn’t pitched competitively since throwing five innings in a spring training game on March 23.
"We want to cover our pitching right now and see where the next couple days take us," Hurdle said. "We just want to make sure we have enough. We’ve got Lyles coming back. We need to protect the pitching."
Hurdle said the team worked infielders Kevin Newman and Colin Moran in the outfield before Thursday’s game for emergency depth. The Pirates were already missing Gregory Polanco (left shoulder surgery) and Lonnie Chisenhall (right index finger fracture) from their outfield.