FOXBOROUGH, Mass. — Tom Brady. Rob Gronkowski. Shane Vereen. Aqib Talib. Rob Ninkovich. Devin McCourty.

They are some of the New England Patriots’ marquee players.

But as New England prepares to play Peyton Manning and the Denver Broncos on Sunday night at Gillette Stadium, the most important player on Coach Bill Belichick’s roster this week might be Ryan Mallett.

Ryan Mallett?

The backup to Brady?

Yes, Ryan Mallett.

You see, this week, Mallett is Manning.

Confused?

Well, as the defense tries to get a feel for what the unstoppable Broncos might do, Mallett is playing the part of Mr. Manning on the scout team. It’s his job to mimic Manning, right down to the pre-snap gyrations and gestures Manning performs on every snap.

“It’s not easy,’’ said Mallett, who in his three-year career with New England has appeared in four games and thrown four passes, one complete for 17 yards, one intercepted.

But it is essential. And important.

The Patriots need to simulate, as best they can, not only the formations but the pace of Denver’s offense. They need to simulate the Broncos’ players, which won’t be easy.

Denver has the NFL’s most prolific offense. The Broncos lead the league in points per game (39.8), total offense (455.5 yards) and passing (350.4 yards). Manning has thrown for 3,572 yards and 34 touchdowns already, with only six interceptions.

Denver’s top four receivers – former Patriot Wes Welker (61 catches, 648 yards, nine touchdowns), Demaryius Thomas (60 catches, 914 yards, nine touchdowns), Steve Decker (54 catches, 792 yards, three touchdowns) and Julius Thomas (45 catches, 590 yards, 10 touchdowns) – have more receiving yards than the Patriots’ top receiver, Julian Edelman, who has 500.

They are on pace to shatter many of the records Brady and the Patriots set in that remarkable 2007 season.

So Mallett needs to be pretty precise in his imitation of Manning.

“I just study him as much as I can and try to do exactly what he does, when he does it, how he does it and where he would do it,’’ said Mallett.

That means putting in some extra practice time.

“I don’t know how much time, what amount (of his practice), but it’s definitely not just going in and watching him on film one time and you know what he’s doing,’’ said Mallett. “You’ve got to see the intricacies he brings and how he does it.’’

Obviously Mallett doesn’t have Manning’s talent. Manning is heading to the Hall of Fame when he retires; Mallett has yet to start an NFL game.

But Mallett apparently knows Manning well. He simulated Manning last year when the Broncos came to Gillette and was awarded a game ball for his efforts after the Patriots won, 31-21.

The fact that they’re similarly sized – Mallett is 6-foot-6, 245 pounds; Manning is 6-foot-5, 230 pounds – helps. He gives the Patriots’ defenders a good look at what Manning would look like in the pocket. And Mallett has a strong arm so he can simulate Manning’s deep balls or sideline throws.

There are others, however, that Mallett has a hard time copying, like Carolina’s Cam Newton, whose running ability is something that few backup quarterbacks would be able to simulate.

“I just try to do what I can do that they do,’’ said Mallett, a third-round pick out of Arkansas in 2011 (and a close friend of Red Sox infielder Will Middlebrooks). “I know my abilities. But if I’m playing somebody else, I put my stuff to the side for a little bit and try to do what they do.’’

What Mallett and the rest of the scout team does is very important, according to Belichick.

“We take our players on the scout team and we put them in positions that approximate what they have or what they do,’’ he said. “Receivers play receiver, tight ends play tight ends, backs play backs. Sometimes you have certain receivers simulate certain guys depending on the team you’re playing, sometimes you don’t. But whatever it is, you try to put the best look you can out there.’’

Steve Gregory, the injured Patriots safety (who may play Sunday with a cast on his broken right thumb), certainly appreciates everything Mallett does.

“Ryan does a great job,’’ said Gregory. “Obviously you can never replicate fully what a team does because they have their players and we have our players. All you can do is try to give the best look you can, try to understand their schemes and the things they’re trying to do, have a good game play and when you go out on Sunday, communicate and execute and try to put it all together.’’

In the end, said Gregory, it comes down to what happens on Sundays.

“You try to simulate the best you can, you try to pair up guys who are similar in size and such,’’ he said. “But the only time you’re going to really, truly get the look is on Sunday, when you line up against those guys.’’

Mike Lowe can be reached at 791-6422 or at:

mlowe@pressherald.com

Twitter: MikeLowePPH