New York Giants linebacker Antonio Pierce believes Mathia Kiwanuka is more than capable of solving the Giants' defensive crisis after Michael Strahan decided not to come out of retirement yesterday.

The Super Bowl Champions had contacted Strahan about a possible return when Pro Bowl defensive end Osi Umenyiora was ruled out for the season on Sunday with a knee injury he picked up against the New York Jets.

Unlike Brett Favre however, Strahan hasn't been pushing to return to the game and has decided against a 16th year with the Giants, and the $8 million contract that would have gone with it.

Far from being down-hearted however, Pierce is confident that Kiwanuka, a first round draft pick in 2006, is more than capable of filling the big shoes left by Strahan and Umenyiora.

"There is a reason he went in the first round obviously," middle linebacker Pierce said. "The guy, he is playing behind Strahan and Osi, and then we moved him to linebacker, so obviously he is one of our top players on the team and he is going to show that he is a top defensive end in the league."

Pierce also said the team is ready to move on without Strahan, the team's sacks leader who retired in June, four months after earning his first title ring.

"We know we are a confident team and we are a playoff-capable team and we have to go out and perform like it," Pierce said. "The reason we took the (underdog) role last year was because everybody said it, and we just went with it. We're not thinking like that this year. We do have a chip on our shoulders and it grows more and more when somebody gives us something to feed off of."

While the Giants defend their title, Strahan will watch from the sidelines in his role with at Fox Sports on their NFL pregame show on Sundays, a job paying $2 million.

"This has been one of the toughest nights of my life," Strahan said. "But after long deliberation and throwing around a million scenarios in my head for the past day, I think it's just best if I stay retired."

Giants general manager Jerry Reese had asked the 36-year-old Strahan to reconsider his retirement on Monday, just 48 hours after the Super Bowl champions lost Pro Bowl defensive end Osi Umenyiora for the season to a knee injury in the pre-season game against the New York Jets.

Strahan needed just a day to turn down an offer to return for a 16th season with what could have been an $8 million contract.

"I really love my life now," he said. "It's great having nobody put a finger on me. You really put yourself through an awful lot in this league, more than people realise."

Reese did not seem surprised by the decision.

"We knew it was a long shot, but we owed it to ourselves to exhaust the possibility," Reese said. "We appreciate Michael even considering ending his retirement. He has a new career in front of him and we wish him nothing but the best. As we all said when he announced his retirement, Michael was and is a great Giant."

The Giants moved Mathias Kiwanuka from linebacker to defensive end on Monday to take over for Umenyiora, who had successful knee surgery yesterday morning and was placed on season-ending injured reserve.

The move will not be a major one for Kiwanuka. He was drafted in the first round as a defensive end and started nine games as a rookie. He also lined up as a defensive end in third-down situations.