FOXBORO – Bill Belichick made the call, Junior Seau answered, and just like that the 40-year old linebacker left his surfboard-and-sports-dad lifestyle behind.

On Wednesday, the secret everyone knew was "revealed" — the Patriots re-signed Seau, who was on the practice field in the afternoon, at one point laying on his belly and pretending to paddle the surf with his hands as he chatted with Vince Wilfork and rookie Ron Brace, to begin a 20th season in the NFL.

He is back for a fourth time, and it is almost as though he had never left.

"I walked in at 6:45, and he was already in (the weight room) in like a full sweat," Tom Brady said. "He hasn't changed at all. He brings a lot of energy to the team and excitement. Attitude is everything with Junior. He's a great professional and he shows great leadership. And he's a playmaker. There's a guy that there's only one of him. There's only one of him that's ever played and I'm glad he's back on the team."

Seau dismissed the notion that he was doing anything special by being at Gillette Stadium so early. He wakes up nearly every morning to work out at 5:30, and after so many years as a professional football player, that may never change.

The story of how Seau came to New England initially is well-known by now. In 2006, just days after an emotional (there seems no other way for him to do things) press conference, Seau announced not that he was retiring from the Dolphins and the NFL, but that he was graduating.

He had barely turned the tassel on his mortarboard when Belichick called the first time, offering him a chance to return to football class. And a great relationship was born.

Belichick has a tremendous affinity for certain players, and Seau is one of them. And Seau seemingly would go on any adventure Belichick would lead him on. After a broken arm cut short Seau's first season in New England, he came back for a second in 2007. Last year, it seemed his playing days might actually be done, but with four weeks to play in the season, Belichick came calling again.

This year, murmurs of yet another post-grad season for Seau began weeks ago — and Belichick admitted on Wednesday that bringing him back is something that had been talked about "for quite a while." According to Seau, Belichick told him just to be ready for a call, but the timetable was all

Seau has made it clear, both last year and this year, that the only team he would ever come back with at this point is the Patriots. He trusts Belichick, knows New England's system, and knows the Pats' locker room.

So now he's back, and whatever Belichick needs, Seau will try to provide.

"On and off the field, the best thing I do is I lean on Bill Belichick," he said. "He has a plan. His plan is something that we're going to try and implement — whatever it may be. He knows who I am, I know what he has to offer. I trust Bill. Because I trust Bill, I'm here today.

"What am I going to do? How am I going to help the team? You know, I can't forecast that. I wish I could. If I could, I wouldn't be a football player. Just give me a helmet. I guarantee you I'm going to be the best player that I can be today and we'll build from there."

Seau wasn't able to get his old locker back — the one in the corner that now belongs to Jerod Mayo — but he was able to get his old number back. Derrick Burgess had been wearing number 55, but through a little buttering up (Seau joked that he gave Burgess a hug first to soften him) and possibly some dinners for his fellow linebacker, he was at practice wearing his usual number.

While no one was ready to say where Seau will play when he does take the field, and that could very likely be this Sunday, it seems safe to assume he will be a situational-type player, and there is now speculation that the Patriots may play more of the 3-4 alignment they have customarily played under Belichick.

Mayo and fellow second-year player Gary Guyton are currently New England's top two players at inside linebacker, and Seau could rotate with Guyton, which would mean a shift back to his natural outside position for Adalius Thomas, with Pierre Woods or possibly Tully Banta-Cain playing opposite him.

Seau joked that he is joining a position group so young that they were in first grade when he began his career, though even that is not quite true: Mayo and Guyton are both just 23, meaning that they were barely in preschool when the Chargers made Seau a first-round draft pick in 1990.

He is impressed with Mayo, saying the "sky is the limit" for the team captain, and also lauded Guyton's recent play in Mayo's stead while he was out with a knee injury.

Though he has yet to play a down this season, Seau was asked how much longer he thinks he can continue to play. Again, though, he indicated that that's really not up to him.

"Tell Bill stop calling and I won't answer," he joked.

smanza@projo.com