Halladay, who turned 35 Tuesday, had surgery on his right (pitching) shoulder Wednesday. He is being treated for labrum and rotator cuff problems and also had an inflamed bursa removed, the team said Thursday.
"He'll begin a progressive rehabilitation program and if all goes well, he may possibly begin a throwing program in 6-8 weeks," said Dr. Michael G. Ciccotti, team director of medical services.
Halladay won back-to-back Cy Young Awards in 2010 and '11 while with Philadelphia, but is 2-4 with an 8.65 earned run average this season. He last pitched May 5, a game in which he was charged with nine earned runs in 2 1/3 innings.
In a 16-season career, which includes 12 years in Toronto, Halladay is 201-104 with a 3.37 ERA. He also won the Cy Young Award in 2003 while pitching for the Blue Jays.