CLEARWATER, Fla. -- A notable absence Thursday at Bright House Field?

Chase Utley.

Phillies general manager Ruben Amaro Jr. said Utley left the team Tuesday night to see a rehab specialist, although Amaro declined to reveal the specialist's name or location. Utley is sidelined indefinitely with patellar tendinitis, chondromalacia and bone inflammation in his right knee.

Phillies athletic trainer Scott Sheridan accompanied Utley on the trip. They are expected to return Thursday night.

"We're just trying to give him new techniques and new things to work on, so we can try to help him improve his comfort," Amaro said.

Amaro said Utley has taken "baby steps" forward, but any progress sounds small.

"There's no regressions," Amaro said. "We're just trying to do everything we possibly can to avoid any types of surgeries."

One question that has been asked repeatedly since Utley's injury became public is this: Why not have surgery now? Even if he misses a few months, he could be healthy and ready to play the second half of the season.

"Well, what you said would make sense," Utley said March 9. "But it's not that cut and dried."

"It's not that cut and dried," Amaro said. "There are a lot of risks any time you have surgery. And especially in this area with some of the things that are going on with his knee, there's a risk it would cause more damage."

The risk of making the knee worse is why the Phillies and Utley are exhausting every treatment possible.

"We're just going to be as cautious as we possibly can and try to be as conservative as we possibly can to try to get through it," Amaro said.

Amaro said he still expects Utley to play this season, although Utley is expected to open the season on the 15-day disabled list.

Amaro offered no timetable for Utley's return.

Could he be back before the All-Star break?

"I don't have any idea," Amaro said. "It could be weeks. It could be months. It could be days. I couldn't give you any timeframe whatsoever. None."

Utley continues to take batting practice without pain, but has been unable to run or take fielding practice, although he has sat on a bucket and fielded ground balls.