FOXBOROUGH, Mass. – The New England Patriots aren’t certain whether Michael Vick or Vince Young will be under center for the Philadelphia Eagles on Sunday.

One thing is for sure, though: LeSean McCoy will most definitely be lined up in the backfield, and that’s enough to capture the defense’s attention.

“This is by far the most elusive back that we’ve been up against so far this season,” Patriots defensive end Andre Carter said. “Looking at film, it looks like he’ll lose yards to gain yards, then those are the tackles on a running back that you hate.

“Just as a defense, we always mention just kind of swarming and gang tackling, and that’s what it’s going to take for four quarters.”

Vick, whose sensational season in 2010 led to the Eagles (4-6) signing him to a lucrative long-term contract, has two broken ribs and missed last week’s win against the New York Giants. He has yet to practice any drills this week and is questionable on the Eagles injury report.

In all likelihood, it will be Young making his second start of the season after valiantly stepping in last week and leading the Eagles to a 17-10 victory, perhaps a pivotal win that kept their playoff dreams alive.

Philadelphia coach Andy Reid said Young has taken all the reps with the first-team offense in Vick’s absence this week.

Young might not be as versatile as Vick, but both boast a strong set of legs that have defined the bulk of their careers. Combine that with McCoy, who has scored a rushing or receiving touchdown in nine of the Eagles’ 10 games this season, and the New England defense is in for a gritty test.

“Speed, that’s all I can really tell you,” said Patriots defensive tackle Kyle Love. “Speed kills. In this league, it definitely kills.”

Despite the Patriots’ (7-3) trotting out the worst pass defense in the league, allowing just shy of 300 yards a game, they expect a heavy dose of McCoy on Sunday.

And with good reason.

A dual threat to run or catch the ball out of the backfield since his rookie campaign in 2009, McCoy is the lone running back in the league this year to have already eclipsed 1,000 yards rushing while guiding the league’s top-ranked rushing attack at 168.0 yards per game.

“He scores a lot of touchdowns, he’s a great player,” said New England linebacker and defensive captain Jerod Mayo. “He’s never down until multiple people tackle him. He’s a threat out of the backfield to catch the ball as well, so he’s a great threat to the whole defense.”

New England coach Bill Belichick thinks McCoy might even be better than former Philadelphia running back Brian Westbrook.

“This guy is pretty good,” Belichick said. “I’d say he’s quicker than Westbrook. Westbrook might be a little stronger, I don’t know. This guy is a handful now.

“You don’t see really anybody tackle him one-on-one. You need a group of guys around him. He gets hemmed in and then he gets out of it. He’s got some running strength, too. He gets through the line. Guys get a shot at him and he’s able to run through them.”

While McCoy is on pace for a career-high in yards, just 61 shy of his career-best set last year with 1,080, and already has nearly as many rushing touchdowns (10) as his first two years combined (11), his receiving rampage has tapered off a bit. With 34 receptions for 198 yards and two touchdowns already under his belt this season, he is well off his league-best reception total for a running back last year, when he hauled in 78 catches.

The defense, more than usual, also will be after the ball, especially with the uncharacteristic manner in which McCoy loosely carries it. It hasn’t hindered him yet, however, with no fumbles in 188 attempts this year and only three in 550 career carries.