"It feels great," said Winfield, who receives $16.1 million in guaranteed money in the deal. "I've got no worries. I'm excited."
Winfield's 2009 salary was revised as part of the extension, and he's scheduled to receive $30 million over the next four years. After the third year, the contract contains decelerators if Winfield is a nickel or dime back and accelerators if he's still a starter.
Winfield was heading into the final year of a six-year, $34.8 million contract, and the sometimes contentious negotiations between him and the Vikings broke off at one point during the summer. It was starting to look a lot like the experiences of Sharper, who left to sign with the New Orleans Saints, and Birk, who declined an offer from the Vikings to join the Baltimore Ravens.
Winfield skipped the Vikings' optional workouts this summer in protest of the stalled contract talks, and he also missed a mandatory minicamp in June.
Ashanti Webb, Winfield's agent, said the problem in contract negotiations was the uniqueness of his client's situation. Winfield is 32 and heading into his 11th NFL season, which typically is the beginning of the end of a cornerback's career.
"We just had a tough time putting this thing together because we didn't have anything to go by," said Webb, who met with Vikings officials Wednesday afternoon.
Webb looked all the way back to talks between the Washington Redskins and Hall of Fame cornerback Darrell Green, who played at a high level for 20 seasons. Webb used that to build a framework for Winfield's deal.
"It was never a situation where they didn't want to do it or we didn't want to do it," Webb said. "It really was unprecedented."
Winfield is coming off one of his best seasons as a pro. He had 95 tackles, four forced fumbles, two interceptions and two sacks last season to help the Vikings win the NFC North title, and he also earned his first Pro Bowl nomination.
Despite putting his body through plenty of punishment as one of the NFL's hardest-hitting cornerbacks, the 5-foot-9, 180-pound Winfield said he has plenty of football left in him with Vikings training camp beginning July 30 in Mankato, Minn.
"I feel great," Winfield said. "I've been working out down in Houston the last six weeks. I have no injuries, a clear mind. I've been playing this game a long time, and I have a lot left in me."
The new deal allows the Vikings to keep a valued locker-room leader and one of the league's most physical cornerbacks while also allowing Winfield to stay in a place, and a defense, where he has flourished.
"That was the goal," Winfield said. "I've been here since '04. I'm very comfortable with my teammates, the coaches, the city. It gives me an opportunity to win a championship."
Now Winfield can concentrate on going after that title. The Vikings lost to the Philadelphia Eagles in the first round of the playoffs last season, but Winfield said the team expects to contend for the NFC championship this coming season.
"We have all the pieces in place," Winfield said. "We have no excuses."
The news came on the same day that the Vikings signed third-round draft pick Asher Allen, who could be Winfield's eventual replacement, to a four-year deal. Financial terms of the deal weren't disclosed.
NFL Network's Jason La Canfora, NFL.com's Steve Wyche and The Associated Press contributed to this report.