Giants defensive end Osi Umenyiora underwent arthroscopic surgery on his troublesome right knee Friday morning, according to the team. "It's a simple debridement," said Ronnie Barnes, the team's vice president of medical services. Barnes said Umenyiora's recovery time is expected to be approximately three to four weeks, but a person close to Umenyiora told ESPN's Adam Schefter that "it could be four to six weeks or longer."