Updated

The career of St. Louis Cardinals starting pitcher Chris Carpenter may be in jeopardy going forward.

At a Tuesday press conference, Cardinals general manager John Mozeliak revealed he doesn't expect the former Cy Young award winner to pitch for the team this upcoming season, calling it "very unlikely" as the 37-year-old continues to have discomfort from last year's medical issues.

Last season, Carpenter had been sidelined since spring training before choosing to undergo surgery in July to relieve a nerve-related issue in his throwing shoulder. He was expected to miss the remainder of the 2012 season, but came back to make three regular season starts at the end of the campaign as well as three in the postseason.

However, the right-hander has since told management he experienced setbacks while intensifying his throwing program in preparation for spring training, and multiple sources with further knowledge of the pitcher's situation have said Carpenter is contemplating retirement.

At the press conference, Mozeliak added, "At some point, he'll start reflecting on the next chapter of his life" but it won't be decided today.

Carpenter, a three-time All-Star, won the Cy Young in 2005 and after missing large chunks of the 2007 and '08 campaigns due to ongoing elbow problems, returned in 2009 to finish 17-4 with a career-best 2.24 ERA and claim the Comeback Player of the Year award. He was also a major contributor in helping St. Louis to World Series titles in 2006 and 2011.

Over his 15-year career, Carpenter has pitched more than 2200 innings in amassing a 144-94 overall record and a career 3.76 earned run average with the Cardinals and Toronto Blue Jays.