Knicks guard J.R. Smith has had patella tendon surgery and arthroscopy on his left knee that likely will keep him from joining the Knicks when they open training camp in late September.

The team said Smith will need 12-16 weeks to recover from the operation performed Monday by Dr. Answorth Allen at the Hospital for Special Surgery. The team said the injuries were chronic, with the arthroscopy repairing a tear in the lateral meniscus.

Smith, who won the Sixth Man of the Year award, helped shoot the Knicks into the playoffs before struggling in the post-season. The New Jersey product worked out a deal to stay with the Knicks that will pay him about $25 million over four years.

He averaged 18.1 points during the regular season, second on the team behind Carmelo Anthony.