New York Knicks power forward Amar'e Stoudemire had an unreported "clean-up" procedure on one of his knees in July, according to the New York Daily News.
It is unknown which knee was operated on, but Stoudemire had surgery on his right knee in October and on his left knee in March.
Stoudemire, 30, was limited to just 29 games last season because of ongoing problems with both of his knees. He is entering the fourth season of a five-year, $100 million contract.
The 2002-03 rookie of the year is a six-time All-Star, but the Daily News notes the Knicks are "all but resigned to the fact that Stoudemire will never return to his All Star form on a consistent basis" because of his physical problems. In fact, New York acquired power forward Andrea Bargnani from the Toronto Raptors and re-signed power forward Kenyon Martin during the offseason.
In his 11-season NBA career, Stoudemire has averaged 21.3 points and 8.6 rebounds per game, but those averages have dipped in each of the past two seasons.