Source: Kevin Kolb unlikely to play

Kevin Kolb's return to Philadelphia on Sunday likely will be as a spectator instead of as a participant.

The Arizona Cardinals' quarterback is not expected to play Sunday against the Eagles, his former team, due to his right turf toe injury, a league source told ESPN NFL Insider Adam Schefter.

John Skelton is expected to start in Kolb's place for the second straight week.

Kolb failed to practice again on Thursday, though he insisted there has been "dramatic improvement" in his toe.

Coach Ken Whisenhunt raised the possibility that there could be a game-time decision to dress Kolb as the backup quarterback, even if he is unable to practice for the second week in a row.

"I wouldn't say that he has to (practice) but I would like for him to," Whisenhunt said. "It's all going to be a function of how much more he can do on his foot. He's made good progress but we have to make sure that he can, like we said, still be able to drop and move."

Kolb was upbeat on Thursday, though. He said he's moving better and is improving his ability to push on the injured foot, which he plants while passing.

"That's what we're seeing dramatic improvement in the last couple of days," he said.

While the decision could inevitably be to start Skelton, the question of whether Kolb is healthy enough to be the backup ahead of Richard Bartel might not be answered until Sunday.

"It could go to game-time to where he would be in a backup role," Whisenhunt said. "You could think of it that way. It's really going to depend on how comfortable he is with the plan and if he can do anything or not as we continue to build off of that as the week progresses."

Kolb started seven games in four seasons with the Eagles and was heir apparent to Donovan McNabb before the signing of Michael Vick.

Kolb started last season's opener, but was sidelined by a concussion. Vick has been the starter ever since.

At his request, Kolb was dealt to Arizona in the offseason, and signed a five-year, $63 million deal, with $21 million guaranteed.

Injured two games ago at Baltimore, Kolb didn't practice last week and sat out Sunday's 19-13 overtime victory over St. Louis. Although he didn't work out officially Wednesday, either, he said he was able to do a little bit to prepare.

Skelton, while far from spectacular against the Rams, did help the Cardinals snap a six-game losing streak.

Although Skelton was responsible for two safeties, he came back to lead an 84-yard drive that ended with his 13-yard touchdown pass to Larry Fitzgerald to tie the game.

Information from The Associated Press was used in this report.