Alcantara felt renewed forearm tightness following his rehab start Thursday with Triple-A Jacksonville, Jordan McPherson of the Miami Herald reports.
Alcantara is headed to Miami to be evaluated this weekend by the Marlins' medical staff, and it's a safe bet that he is not going to be able to return before the end of the regular season. He tallied four strikeouts over four scoreless innings Thursday with Jacksonville while touching 98.3 mph with his fastball, but the right UCL sprain that sent him to the injured list Sept. 6 is still clearly an issue.