NEW YORK (Reuters) - The New York Giants could be without defensive end Osi Umenyiora for their season opener in September as he begins a three-to-four week recovery from arthroscopic surgery on his right knee on Friday.

Giants general manager Jerry Reese said the two-time Pro Bowler, who hit the practice field this week despite a contract dispute, was bothered by swelling in his balky right knee after going hard in his return.

"After practicing for three days he had some swelling in the knee." Reese told reporters. "Osi's feeling is he wants to get it cleaned up now because he is looking forward to playing this season, and he wants to (play) without the knee being an issue for him."

Umenyiora reported to training camp one day late and then stayed away from the practice field disgruntled by what he felt was a broken promise by the team to renegotiate his contract. He relented and went back to work in earnest on Monday.

The 29-year-old Umenyiora, who shared the team lead with 11.5 sacks last season, said it was better to have his knee cleaned up now rather than later.

"It was going to have to be done, the only question was when," said Umenyiora. "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."

The Giants open their regular season against the Washington Redskins on September 11.

(Reporting by Larry Fine, Editing by Frank Pingue)