Marcum recently underwent season-ending surgery to reliever numbness and tingling caused by thoracic outlet syndrome, which he was diagnosed with by doctors last month. The syndrome means that Marcum likely had an artery that impeded on circulation in his right arm.
The Mets signed Marcum to a one-year contract worth $4M plus incentives this past offseason. By releasing Marcum, the Mets saved at least $500K instead of placing him on the 60-Day DL>
Marcum struggled in 2013, compiling a 1-10 record with a 5.29 ERA with 60 strikeouts and a 1.35 WHIP over 78.1 innings in 14 appearances, 12 of them starts.