The knee has bothered him since the final weeks of last season.

"His knee is bothering him so bad," a friend said.

He said the knee did not bother him during the tournament, and nothing else seemed to, either.

His left knee has bothered him all season and sometimes swells up.

"My knees were bothering me yesterday, but I'm fine today."

Houston said the knee had been bothering him for about a week.

"The surgery was two years ago and the knee never has bothered me since," he says.

His knees were bothering him a bit, but other than that he looked great.

Recently, his left knee has bothered him so much that he plans to have surgery on it this winter.

The knee was bothering him the last couple of days more than ever.