Updated

The New York Mets placed pitcher Shaun Marcum on waivers for purposes of his unconditional release on Tuesday.

Marcum was placed on the disabled list on July 9 after being diagnosed with thoracic outlet syndrome, which is a blockage in an artery that has caused lingering pain and numbness in his pitching hand, neck and upper back.

The 31-year-old Marcum underwent successful surgery to address the injury, but will not be available to pitch this season, causing the Mets to release the right hander.

Marcum's 2013 season did not begin until late April, when he was activated from the 15-day DL after being sidelined with a neck injury.

Things did not go well from there, as he pitched to a 1-10 record and 5.29 earned run average in 14 games (12 starts).

The 31-year-old signed with the Mets in January after spending the previous two years with the Milwaukee Brewers, going 20-11 with a 3.60 ERA in 54 starts.