FOXBOROUGH - Side by side in the snow last Sunday, the Patriots had rookie Jerod Mayo and veteran Junior Seau starting at inside linebacker. The fact that the nearly 40-year-old Seau was suiting up alongside the 22-year-old Mayo is more than remarkable; it's improbable, considering that 18 days earlier Seau awoke in sunny San Diego as a surfing civilian and devoted dad.
"Coming in here with guys that were  years old when I was a rookie is a great challenge to me, and to be out there running around with these kids is unbelievable," said Seau, who began his NFL career in 1990.
What Seau, the NFL's answer to Dorian Gray, is doing is incredible. After sitting out the first 13 weeks of the season, he answered an SOS from Patriots coach Bill Belichick and signed on for a 19th season. In less than a month, he has gone from being out of the game to starting for a team that will play for a chance to make the playoffs Sunday in Buffalo against the Bills.
The Patriots (10-5) are in the playoffs if they win against the Bills and either the Dolphins or Ravens lose. New England can also get in with a tie plus a loss by Miami or Baltimore.
It's tough to say which is more unlikely, the fact that the injury-racked Patriots are in position to make the playoffs or that Seau, who before signing Dec. 5 hadn't participated in football since Super Bowl XLII last Feb. 3, is in it with them.
"A lot of people thought it was undoable," said Seau, who turns 40 Jan. 19. "A lot of my friends even called and were chuckling. They were funny about it. They thought it was funny. There were a lot of people that didn't believe it could work.
"I respect the game. The game is not something where you come off the street or come off a surfboard and jump into it and go pound your chest. To be able to have 19 years under your belt, managing the game is something I believe in, and I always tell people my experience and knowledge of the game is so much faster than my 40 time. And it's been that way for six years, so I think I'm OK."
Seau, a 12-time Pro Bowler and future Hall of Famer, wouldn't be here if it weren't for the bond he built with the Patriots during his previous two seasons in the organization and the mutual respect he and Belichick have.
When Patriots owner Robert Kraft presented Seau with his AFC Championship ring Oct. 12 at the linebacker's eponymous restaurant in San Diego, Seau stated at the time that the only team he would come back for was the Patriots.
The call came from Belichick on the night of Dec. 3. Seau checked with his 15-year-old daughter, Sydney, and two sons, Jake, 13, and Hunter, 8, all of whom told him, "Dad, go get it." He was on a plane to New England the next day.
"I got here," said Seau, "and Bill threw a playbook at me and said, 'Check and see what wrinkles we threw in from this year and get ready for Seattle. You're suiting up.' I was like, 'All right, let's roll.' "
Two days later, he was on the field at Seattle, playing as a reserve, his preparation consisting of one practice and a walkthrough in the ballroom of the Renaissance Seattle Hotel.
Seau was supposed to provide depth as a situational player for a depleted linebacker corps, but that changed in the Seattle game when Tedy Bruschi, who was already bothered by a left knee injury, took a helmet to the knee. Bruschi hasn't played since.
In Seau's second game, he played 50 of 65 snaps in a 49-26 win over the Raiders, recording five tackles.
Last Sunday, with rookie Gary Guyton (ankle) unable to go, Seau became the eighth linebacker to start for the Patriots this season. He responded by tying Mayo for the team lead in tackles with seven and playing 40 of 52 snaps (including penalties).
As linebacker Mike Vrabel commented earlier this week, "There were no training wheels" for Seau or outside linebacker Rosevelt Colvin, who was signed two days before Seau and has gone from the street to a starter as well.
"Roles have changed," said Seau. "We're thinking that we're going to kind of have time to build into it, and it's pedal to the metal, press the gas and let's go. So it's definitely something I'm going to look back on when everything is said and done as one of the biggest accomplishments [of my career]."
Sunday will mark the 261st game of Seau's career, and if the Patriots lose, it could be the last.
"Never say never," said Seau.
Playoffs or end of the season Sunday, the Patriots and Seau can walk away with their heads held high. Nobody thought either one would reach this point this season.
"My quest was to come and help this team win the next four games, and we have an opportunity to do that," said Seau. "We'll see what happens after that.
"No one expects us to do what we're doing now, and we have an opportunity to finish this off on a high note, and to have 11 wins would be very special with everything that has gone on. And if that's the end of the road in terms of this year, then we can at least hang our hats and know that we did a heck of a job leaving this stage."
Christopher L. Gasper can be reached at email@example.com