Cowboys' Brandon Carr in a stopper role

IRVING, Texas -- Brandon Carr has made his bones the last three games matching up nearly all of the time against Demaryius Thomas, Pierre Garcon and DeSean Jackson.

None of them reached the end zone against the Cowboys, despite being their quarterback’s big-play receiver, go-to receiver or speed threat.

A lot of credit goes to Carr, who has play has improved with the more man coverage he has played.

But why isn’t it just a given that he follows the No. 1 receiver all the time? They play box-and-1 defenses in basketball.

Jason Garrett offers up the reason:

“Because you don’t play man-to-man coverage every snap, so if you don’t play man-to-man coverage every snap and you play zone and you move guys around, it’s a great indicator to you as an offensive player that they’re playing man,” Garrett said. “If he follows him all over the place then it’s probably man. Then you have to get into the realm of ‘OK, we’ll move him over and then we’re going to play zone from that look.’ Well, he hasn’t done that very much. If they move the guy around, it presents some problems. So it has to be a really viable, viable receiver on the other side, a guy who is really threatening you to do that, then you have to deal with some of the other things that go with it.”

So is Calvin Johnson of the Detroit Lions a viable threat?

“That’s a fantastic question,” Garrett said, smiling and well aware that Johnson is as elite as they come in the NFL.

And look for Carr to follow Johnson all over Ford Field on Sunday.