"Blake Ayles is going to get operated on on Monday," Carroll said. "We tried to get him back but we are going to see what happens if we scope him.
"He's got a little chip underneath his kneecap."
Ayles suffered the injury when he collided with USC quarterback Mark Sanchez weeks ago and has tried to play through the pain.
"They have known that he has had a little issue but they were trying to see how long he could play through it," Carroll said. "It's just too uncomfortable."
Carroll said Ayles could be back for the bowl game.
"We'll see how soon we can get him back," Carroll said. "Maybe we can get him back before the bowl game."
Ayles has 6 receptions and a touchdown in 2008.
"He's not going to make it," Carroll said. "He just didn't respond to the work."
The veteran leader of the defense will be forced to miss Senior Night on Saturday.
"He's really frustrated by it, but he can't get back yet," said Carroll. "We will see where he is next week."
News and Notes
• Freshman defensive tackle Armond Armstead didn't practice on Thursday and Coach Carroll doesn't expect him to play Saturday.
• The Sanchez Family will be hosting Thanksgiving dinner for all the out-of-state players on the team that couldn't be with their families today.
• Joe McKnight was back at full speed after suffering a shoulder stinger on Wednesday.
• Toy Drive: Pete Carroll's charity, A Better LA, will be having a toy drive at the USC vs. Notre Dame game. The collection point for donations or new unwrapped toys or USC gear will be in front of the statues at the Coliseum at the ESPN booth/tailgate location.
Taylor Mays and Blake Ayles.