On the 15-day disabled list because of inflammation in his throwing shoulder, the two-time Cy Young Award winner met Los Angeles Dodgers team physician Neal ElAttrache on Tuesday, and the procedure will take place on May 15.
"They're going to go in and clean up the bone spur, clean up the rotator cuff and the labrum, try and keep that as (uninvasive) as possible," Halladay said Wednesday before the Phillies played the San Francisco Giants.
"From what I understand, if they go in and see during surgery what they saw on the exams, I have a chance to come back and pitch this year. I have a good chance to come back and pitch this year, hopefully be a lot more effective," he said.
The 35-year-old right-hander is 2-4 with an 8.65 ERA in seven starts this season after missing nearly two months last year because of a strained back muscle.
"They said my range of motion will be better, my location will be better, hopefully the velocity will be better," Halladay said. "They said the cause is a bone spur; the rotator cuff kept rubbing over it. Over time, it gradually created more and more of a tear. They want to get that cleaned up and get that out of there."
Even if he returns this year, Halladay figures to miss a substantial part of the season.
"He said in certain cases it's been three months, but we really don't have a timetable," Halladay said of the doctor's prognosis. "I think the timetable is going to come once they go in and confirm that, hey, what we saw on the X-rays is exactly what we saw when we went in there. They were definitely optimistic that I would be back this year."
If history is any indication, the odds are against Halladay re-establishing himself. According to Fangraphs.com, players over the age of 35 that went on the DL for any sort of shoulder injury only averaged 59 innings over the course of the rest of their career.
Information from The Associated Press was used in this report.