New York Giants defensive end Osi Umenyiora is having arthroscopic surgery on his right knee and likely will miss the season opener on Sept. 11.

General manager Jerry Reese says Friday that Umenyiora "let me know that he wanted to have the surgery now."

Umenyiora has been a headline all summer, as he did not report to training camp with the team following the lockout. Finally, on Monday, he unhappily reported under the terms of his current deal, and worked out for three days before his knee began to swell. Typical recovery for the procedure is at least three weeks, and often four.

"It was better to do it now as opposed to midseason," Umenyiora said in a statement. "It was going to have to be done, the only question was when. If I'm going to miss a little while, I would prefer it be now than at the crucial part of our season. It's the best decision for the team and myself."

Umenyiora reported to camp a day late to protest his contract dispute and was told not to practice with the team while his agents were given persmission to try to make a trade. The team abruptly ended those talks and announced that Osi "says his knee is bothering him."

Umenyiora went to Atlanta to get a second opinion on the knee after the team said he was cleared to return to practice. After three practices, the knee needed repair.

"It is a simple debridement," Ronnie Barnes, the team's vice president of medical services, said, adding that team physician Dr. Russell Warren was to perform the operation at the Hospital for Special Surgery in New York.

Giants coach Tom Coughlin said there is a chance Umenyiora might be ready for the opener at Washington, but that would require a fast recovery. Coughlin said the Giants knew that there was a chance Umenyiora would need the surgery.

"There is no surprise here," Coughlin said. "We'll just keep going."

Reese said that Umenyiora told him on Thursday that he wanted to have the surgery.

"He told me how much he really enjoyed being back on the field this week," he said, "and he's looking forward to getting back out there once he recovers from the procedure."

Umenyiora shared the team lead with 11½ sacks last season and led the NFL with 10 forced fumbles. He was annoyed with the Giants because he alleged that Reese promised to rework his contract, which will pay him $7.1 million through the end of next season.