CLEARWATER, Fla. — Philadelphia Phillies ace Roy Halladay pitched six innings Thursday in his first rehab start since being sidelined by a shoulder injury.

Halladay gave up three runs and six hits in his outing for the Gulf Coast League Phillies against Pittsburgh minor-leaguers. The 36-year-old right-hander struck out four and walked three.

“I am not going to get too far ahead of myself, but I feel good and I feel like each time has gotten better and better,” said Halladay, who is scheduled for a bullpen session Saturday and another minor-league start Tuesday. “So as long as I continue in that direction, I’m fine with that.”

Phillies general manager Ruben Amaro said in a statement that the location of the rehab start will be determined after Saturday’s bullpen session. The Phillies’ minor-league teams in Clearwater, Lakewood and Lehigh Valley all have home games on Tuesday.

“I spoke with Roy today, and with people who were there to evaluate him, and they feel that he continues to make progress,” Amaro said. “He is not as crisp as he wants to be yet. It is likely that he will have at least one more rehab start.”

The two-time Cy Young Award winner had surgery on his shoulder in May to repair a partially torn rotator cuff and remove a bone spur. He also had some fraying of the labrum.

Halladay threw 51 of 87 pitches for strikes. He had recently pitched in a simulated game.

“Really, the goal was to throw as many sinkers and cutters as possible,” Halladay said. “The curveball and changeup just kind of come. So we did. We probably threw well over 80-85 percent cutters and sinkers today, and I thought for the most part the location was pretty good.

“There were times where I’d get in a groove then I’d miss two or three, but really, for the most part, they were on the halves of the plate that I wanted.”

Halladay 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.

“I still feel like there’s more in there, but I’m just very cautious of making sure I’m repeating my mechanics correctly right now,” Halladay said. “I don’t want to try to add on until I’m repeating every time. That’s important for me. I’m still breaking those habits, and I feel like I’m doing a good job of it. I want to make sure I do it the right way.”

All three runs Halladay allowed came during his final two innings.

Amaro also said that starter John Lannan saw a doctor Thursday at the Rothman Institute about his sore left knee and that a stint on the disabled list is likely.

“It appears that he has similar symptoms to those he experienced earlier this season with tendinitis of the patellar tendon,” Amaro said. “We will conduct a repeat MRI tomorrow and will know more about his injury once the MRI is performed.”

Started at The Press in 1993 as an Ocean County reporter. Moved to the copy desk in 1994 until taking over as editor of At The Shore in 1995. Became deputy sports editor in 2004 and was promoted to sports editor in 2007.