PHILADELPHIA -- The Phillies have called Roy Halladay's right shoulder surgery on Wednesday in Los Angeles a success.

But successful arthroscopic surgery does not guarantee he will pitch again this season. Halladay has a long road ahead of him, because he still had his labrum and rotator cuff repaired, as well as an inflamed bursa removed. But Phillies physician Dr. Michael Ciccotti said the organization is "cautiously optimistic" Halladay will be back, because the labrum and rotator cuff were not detached or torn, there were no bone spurs removed and there were no sutures required.

If everything goes as the Phillies hope, Halladay might begin a throwing program in six to eight weeks, which could put him back on the mound for the Phillies as early as late August.

"It was really the best-case scenario in our minds," Ciccotti said. "If and when he feels that he is throwing with the velocity and the control that he's comfortable with and effective, then we'd consider having him be back in a game situation. If all goes well as we and all Phillies fans hope, then it is possible that he may be able to pitch this season.

"But there are a lot of ifs between now and then. Does he get his motion back? Does he feel strong again? How is he when he is throwing a ball? There are a lot of things between now and then that might prevent that from happening."

So it also is possible Halladay will not pitch again this year, and even if he does, there is no guarantee he will pitch with success. Halladay turned 36 on Tuesday and has thrown 2,721 2/3 innings in the big leagues and 641 innings in the Minor Leagues.

FanGraphs.com found pitchers 35 years or older who spent time on the disabled list with any sort of shoulder injury since 2002 averaged only 59 innings the rest of their career. It also found 32 of the 62 pitchers on that list never pitched again. Only six pitched more than 100 innings: John Smoltz (106), Pedro Martinez (153 2/3), Kenny Rogers (173 2/3), John Burkett (181 2/3), Tim Wakefield (424 1/3) and Orlando Hernandez (438 1/3).

Ciccotti said Halladay's biggest obstacles between now and the time that he gets back on the mound are getting his full range of motion back and rebuilding strength in the shoulder.

"Given the person that he is, the motivation that he has, the dedication that he has, he has all the intangibles that are important in getting someone back," Ciccotti said. "But we're realistic about it, too. It is very possible that he is not pitching at the level that he wants or what Phillies fans and his teammates deserve him to be pitching at."

Dodgers physican Dr. Neal ElAttrache performed the surgery. He originally thought a bone spur would need to be removed, but upon looking inside the shoulder, he found Halladay did not have the traditional type of bone spur that rubs down on the rotator cuff. ElAttrache simply smoothed the underside of the bone instead.

"It won't be a problem in the future," Ciccotti said.

ElAttrache told Halladay last week he thought the surgery could turn back the clock a few years in regards to how his shoulder feels. But is that just good bedside manner or is it truly realistic? The statistics certainly suggest otherwise.

"I know he was suggesting to Roy, if everything works out well, and if you have these milder forms of injury, and if you rehab well and you're comfortable, it is possible you may feel the way you felt at the onset of your pain," Ciccotti said. "Rolling back the clock is something that is virtually impossible to do for any of us whether we were elite-level athletes or not. The translation of that is making him feel comfortable enough so he can be effective."

So is Halladay facing long odds?

"There are lots of factors that actually go beyond what happened yesterday that would determine that, and that's clearly a challenge for any elite-level pitcher, even a Roy Halladay, to get back from," Ciccotti said. "As I said earlier, given what was found at the time of the surgery -- best-case scenario -- and given the fact who Roy is and the motivation and focus he has, we certainly hope that happens and it's possible. But there's a lot between now and then to be able to precisely predict how effective he's going to be."