FOXBOROUGH, Mass. -- Some jokingly call him "Senior Seau," and it's easy to see why.
When reporters asked linebacker Junior Seau, who officially re-signed with the Patriots on Wednesday at the ripe age of 40, his impressions of the young nucleus of the Patriots' linebacking corps, Seau joked that most of the guys he's hoping to line up next to this season were probably in the first grade when he was an NFL rookie.
Sorry, Junior, some were even younger.
Second-year players Jerod Mayo and Gary Guyton -- the team's primary inside linebackers -- would have both been 4 years old, preschool age, when Seau was drafted by the San Diego Chargers with the fifth pick in the 1990 draft.
What's more, Seau's addition alone took a previously eight-man linebacking group that averaged 27.25 years of age earlier this week and raised it more than a full year to 28.67 years.
Fortunately for the Patriots, Seau doesn't look like a middle-aged father of three who's spent more time on a surfboard than a football field the past eight months.
"He looks great when you see him," Patriots quarterback Tom Brady said. "He looks like he's 25."
Added center Dan Koppen: "He may be 40, but he's probably 20 at heart. He can run around like a 20-year-old. I'm looking forward to seeing him out there. What he brings, no one can match."
Which is exactly why the Patriots brought Seau back. Patriots coach Bill Belichick called him one-of-a-kind, the sort of praise he's typically saved for the Tedy Bruschis and Troy Browns of the world.
"Junior has a great approach to football," Belichick said. "He has got a lot of energy. He has a lot of enthusiasm for the game. I don't think I have coached too many players -- I'm not saying they're not passionate -- but I haven't coached too many that are any more passionate than Junior is.
"He's a pretty special guy. I think we all know that. Physically, his makeup, his instincts, he's just a football player and a real good one. He's a Hall of Fame guy, and there's not too many of those coming down the pike."
But even Seau seemed to acknowledge that he's unsure what he can bring at this age. All he knows is that he's worked out hard ever since the end of last season in the hope that Belichick would phone with an offer to come see what's left in that tank.
"On and off the field, the best thing I can do is lean on Bill Belichick," Seau said. "The reason why I say that is, he doesn't sit around grabbing a 40-year-old guy off a surfboard unless he has a plan, whatever it may be. He knows who I am. He knows what I have to offer. I trust him.
"What am I going to do? How will I help the team? I can't forecast that. If I could, I wouldn't be a football player. I wouldn't. Just give me a helmet. I'm going to be the best player that I can be today. I promise."
Wearing his familiar No. 55, Seau was back on the field Wednesday during the portion of practice open to the media. He raced through position drills like a first-year rookie and showered himself with a water bottle, oblivious to the chills of a typical fall day in New England.
Asked whether he could be ready for Sunday's game versus the Titans, Seau said simply: "Whatever Bill needs."
What Bill might need most is a mentor to the young linebacking corps. Someone to follow in the footsteps of Bruschi and Rosevelt Colvin, providing veteran leadership in the middle of the defense, particularly late in the season.
It's a role that Seau seems ready to embrace.
"There's a lot of youth [at linebacker], but they can play the game," he said. "If there's anything that I can help them with, either in the meeting room or the weight room, whatever it might take. It's going to be fun.
"But they're definitely young."
Those younger players look up to Seau. Some seemed downright energized and intrigued with the official return of Seau on Wednesday. Fourth-year linebacker Rob Ninkovich arrived at Gillette Stadium to find Seau's entire locker set up -- complete with clothes, pictures and even an "Entertainment Tonight" award -- in a neighboring locker.
"I was excited to hear they had signed him, and I've anticipated meeting him and learning from him," Ninkovich said. "I want to see how he studies the game, how he plays the game. That's all I can ask for: to be around him. Not everyone gets that chance."
Added fourth-year linebacker Pierre Woods: "Leadership, man, leadership. He's been in the league, what, 20 seasons? You can't match that, especially at linebacker, that's amazing."
Last year, Seau signed with the Patriots on Dec. 5 and appeared in the final four games of the season, helping New England go 4-0 during that stretch, though the team missed the playoffs with an 11-5 record.
Seau originally signed with the Patriots as a free agent on Aug. 18, 2006 -- just four days after his so-called "graduation" from the Chargers -- and appeared in the team's first 11 games, making 70 tackles (37 solo) before breaking his right arm and landing on injured reserve in late November.
"I remember when he broke his arm a few years ago in the Chicago game," Brady said. "He ran off holding it. He got on a plane that night and went surfing like two days later. That's how he lives his life."
Seau re-signed with the Patriots the following offseason and served as a team captain during New England's 18-1 campaign in 2007. During his Patriots tenure, Seau has played in 31 games overall, starting 16 of them.
Seau was asked whether he would have considered these recent comebacks if he had gotten a Super Bowl ring in 2007. Seau admitted he probably would not have. But in the same breath, he says he's content to walk away when the time is right.
"It's not tough to leave the game," Seau said. "There's such a great lifestyle that you work so long for to enjoy. I'm not going to cry about cutting up oranges and apples and packing a cooler and going to my son's football game or my daughter's volleyball games and heading home and surfing for three hours. Having a tuna sandwich and playing the ukulele. There's nothing bad about that, so I did not miss it. It's just part of my life. I love life challenges, and I live for those moments. I live for those moments. This is a challenge. I can't forecast what's going to happen; just give me a helmet and we'll work on it."
And he's back for one more challenge and another run at a Super Bowl title. Well, unless Belichick calls next fall. Then he might have to do it all over again.
Asked when he plans to hang up his helmet, Seau said, "Tell Bill: Stop calling, and I won't answer."