Cincinnati Reds righthander Paul Wilson underwent arthroscopic surgery on his right shoulder Friday and is expected to be sidelined for four months. The procedure, which repaired a partially torn rotator cuff and labrum in the shoulder, was performed by Reds medical director Dr. Tim Kremchek. Wilson, who has been on the 15-day disabled list since May 25, has struggled this season, sporting a 1-5 record with a 7.77 earned run average in nine starts. In his last outing on May 16 versus the New York Mets, he yielded seven runs -- six earned -- on eight hits in 5 1/3 innings.