The left-hander, who is dealing with left shoulder tendinitis, is participating in a throwing program but is not throwing bullpen sessions. Marshall was limited to 16 games last season because of the shoulder-related issues.
"He's feeling great but with his history and the shoulder from last year and not feeling great here early in camp, we are going to go on the ultra-conservative side and just make sure he does everything in his throwing protocol to verify that he's feeling great and then get him back on the mound," Price said. "He's not starting from square one. He threw all offseason and threw a handful of bullpens before he got here and three or four bullpens while he was here. He's more advanced than somebody that had to completely shut down for three or four weeks."