FOXBOROUGH – The Patriots are about to find out just how much their young defense has grown up.

They are entering the always hostile Meadowlands to take on another young and talented group — the offense of the New York Jets.

Gone is Brett Farve, replaced by rookie quarterback Mark Sanchez. Gone is veteran possession receiver Laveranues Coles, while second-year tight end Dustin Keller figures to see a much heavier receiving load in 2009.

“He’s a good receiver, a tough guy to stop. I think we’ve seen that all through preseason, definitely last week in Houston,” Patriots head coach Bill Belichick said of Keller.

Indeed, last week in Houston, the second-year tight end out of Purdue caught four balls for a team-leading 94 yards, an average of 23.5 yards per grab.

“[He’s] a very productive player, big guy, runs well, catches the ball well, has a good feel for the passing game. It looks like the quarterbacks have a lot of confidence in him, the ones this year and even last year with [Brett] Favre so, he’s earned their trust and confidence and they look for him. Whatever he’s doing on the practice field, I’m sure it’s something they feel good about. He’s made a lot of big plays in the games.”

While the Bills receiving corps was held in check last week by a Patriots secondary that kept nearly everything in front of them, the Jets have the ability to hurt New England underneath with Keller and running back Leon Washington. Add that to the weapons that already exist in Jerricho Cotchery and Chansi Stuckey, and you’re talking about a diversified offense.

Keller had eight catches for 87 yards in a Jets OT win at New England.

The one constant in the Jets offense is coordinator Brian Schottenheimer. Jets head coach and defensive guru Rex Ryan clearly liked what he saw in the Jets offense from last year and decided to keep Schottenheimer calling the plays.

“I think Schottenheimer’s offense is pretty much the way it’s been,” Belichick said. “I think he modified it quite a bit last year with the change in quarterbacks. You can see what he wants to do and I think that’s shown up every year. He’s had his influence on it at the Jets and even going back to San Diego.”

The Jets offense would be a tough assignment for a good defense on any day in the NFL. But the Patriots are coming in still adjusting to the trade of Richard Seymour in the middle of the defensive line and the loss of stud linebacker Jerod Mayo in the middle of the defense to a right knee injury. And with Tedy Bruschi still in retirement, the two most-experience signal-callers on defense are gone.

So, the Pats turn their hopes to Gary Guyton, who last week stepped into the fold and called signals. And coach Bill Belichick feels the Pats D didn’t miss a beat.

“He’s smart. He’s well-prepared. He has a real good understanding of football — the running game, the passing game. He’s good in coverage. He understands coverage. He understands the running game, he understands defensive adjustments not just his role, but where other people have to be or if somebody else has to do something how that affects him,” Belichick said. “That’s really what you want in a defensive signal caller, somebody that understands how it all works. It’s not always possible. Sometimes you have to have two people on defense do it, one guy with the running game and another guy with the secondary.”

It was obvious in 2008, when Guyton was an NFL rookie out of Georgia Tech, that Belichick trusted the 23-year-old’s instincts since he was active for all but one of the team’s 16 games.

“There’s an element of that regardless, but there’re certain times that the linebackers aren’t involved in coverage — when it’s a blitz or something like that, then it has to be handled in the secondary,” Belichick said. “All things being equal, you want to have somebody that can understand what everybody’s doing out there and make the right decision, rather than make the decision that’s best for maybe the group that he’s involved with, but it’s something that isn’t really what we want to do because it stresses somebody else’s area.

“He understands that quickly. He’s a good communicator and even though he’s played, but he hasn’t played a lot, when he goes in there he plays well and he handles himself well.”