Right-hander Arodys Vizcaino, the well regarded prospect coming off Tommy John surgery who the Cubs got in the Paul Maholm trade last July, had his comeback abruptly cut short by an unrelated issue in the elbow and could be out the rest of the season.

Vizcaino, whose original healthy-spring prognosis already had been pushed back to an expected July debut, had arthroscopic surgery to clean out a calcium buildup in the elbow after Dr. James Andrews examined him Tuesday for recent discomfort.

Vizcaino, 22, is to be shut down for six weeks before restarting a throwing program and probably is looking at a 2013 debut in the Arizona Fall League. Best-case scenario for a Cubs debut seems to be next April.

Vizcaino, who was considered a key part of the Cubs' rebuilding process as a potential impact starting pitcher, was in Chicago during the last homestand to have his throwing supervised by the big-league staff.

The team said nothing then about any issue with the elbow.