SAN FRANCISCO -- New York Mets right-hander Shaun Marcum will undergo season-ending surgery next Monday in St. Louis to address numbness and coldness in his pitching hand, assistant general manager John Ricco said Tuesday.
Marcum was examined Monday by specialist Robert Thompson at Barnes-Jewish Hospital in St. Louis.
Dr. Thompson had performed surgery to repair a clot and damaged artery in teammate Dillon Gee's shoulder last July, which caused hand numbness. He also will perform Marcum's procedure.
Thoracic outlet syndrome is an artery obstruction or nerve pinching caused by compression between the collarbone and first rib. St. Louis Cardinals right-hander Chris Carpenter and Seattle Mariners right-hander Jeremy Bonderman have had comparable issues in their careers.
"It was affecting his ability to grip the baseball," Ricco said.
Marcum was presented with a nonsurgical option involving rehab but opted for surgery, Ricco said.
"That is the recommendation of our doctors as well," Ricco added.
Marcum, 31, may begin tossing a baseball in two months, but would not be ready to pitch again in the majors this season. He had a $4 million base salary and was 1-10 with a 5.29 ERA in 14 appearances (12 starts).
Mets manager Terry Collins said right-hander Carlos Torres will move into Marcum's rotation spot, at least until left-hander Jonathon Niese returns from the disabled list. Niese was cleared Monday to begin throwing after a shoulder injury was deemed not serious by team doctor David Altchek.
The Mets planned to use a four-man rotation for the rest of the first half and skip Marcum's final turn before the All-Star break.
Harvey has been dealing with a blister, although Collins said the All-Star reported improvement Tuesday.
"His finger looked tremendous," Collins said. "I'm very, very happy with what the results were after he had it worked on last night and today. He'll be fine."
Another motivation for potentially skipping Harvey on Saturday is that the Mets are looking for ways to limit his innings count without shutting him down at the end of the season.
Skipping Harvey's final first-half start would help achieve that while also ensuring Harvey is fresh for next Tuesday's All-Star Game at Citi Field.
Collins said the Mets will not go to a six-man rotation once Niese returns in order to curtail Harvey's workload. The manager said that is not practical because the Mets do not have starting-pitching depth beyond Torres. Harvey may be capped at about 220 innings this season.
"[Pitching coach] Dan [Warthen] and I are talking about trying to figure out how to start to cut this guy back a little bit," Collins said. "We'll have to decide what happens on Saturday."
The Mets promoted reliever Gonzalez Germen from Triple-A Las Vegas to take Marcum's rotation spot.
Marcum's loss means both free agents the Mets signed to major league deals last offseason no longer will contribute to the club. The Mets have placed ineffective reliever Brandon Lyon on release waivers.