The surgery was successful, and Roy Halladay may pitch again this season.

But it seems just as possible he may not.

Phillies team doctor Michael Ciccotti addressed the media Thursday afternoon to field questions following the team's announcement that Halladay underwent successful arthroscopic surgery on his injured right shoulder.

Halladay will spend time in a sling and could be ready to begin a throwing program in six to eight weeks. The club's prognosis for a potential return is still about three months. On that front, Ciccotti said on multiple occasions that the club was "cautiously optimistic" about Halladay pitching again in 2013.

But when pressed for specifics on a timetable, the doctor acknowledged that the team will "very careful." There are "a lot of ifs," said Ciccotti, who added "it's very possible" Halladay may not return this season.

"We're going to be so careful with Roy Halladay," he said. "Roy wants to be part of this team but he has to meet certain milestones along the way before he can progress to the next level. If he does that -- if he achieves his range of motion, if he's strong, and he can pick up a ball, and if he progress in what is a very specific tossing program, and he can go through each milestone and feel comfortable enough to go to a mound, and he can pitch, and he's comfortable -- he has to pass each of those tests along the way.

"If he doesn't pass them in a way that we're comfortable and he's comfortable, then we're not going to allow him to go out on a mound and not pitch the way he would want to pitch.

Halladay is in the final year of his contract and could hit the market in the offseason as a 36-year-old coming off seven disastrous starts (2-4, 8.65 ERA) and shoulder surgery. The Phillies, meanwhile, will be without -- at least for a while and possibly for the entire season -- a former Cy Young pitcher they expected to rely on. That's all the bad news.