SARASOTA, Fla. - Reliever Jason Berken tweaked his left hamstring today during conditioning drills.
Berken had left the facility before reporters returned to the clubhouse and wasn't immediately available for comment.
Manager Buck Showalter used the word "tweaked," but added that he wasn't certain of the severity. He was collecting more information from the training staff.
"We'll see where that is tomorrow," Showalter said. "I'm not sure if 'tweaked' is the right description yet. I'll know more after I sit down with Richie (Bancells) after everybody comes in."
Berken is competing for a bullpen spot. He has an option remaining and could end up in Triple-A Norfolk's rotation.
Also, Brian Roberts will take the field with teammates Friday for the first full-squad workout. He'll meet with reporters afterward.
Roberts did some running outdoors earlier today.