David Carter has been working at defensive end this season and could get a chance to play there more Sunday.

Ray Horton likes to have options, so the defensive coordinator will move his players around in practice – cornerbacks playing safety and vice versa, a linebacker playing end, for example – to give the Cardinals leeway if needed.

That's how David Carter, a nose tackle his rookie year, started playing more defensive end this season. And why it could benefit the Cardinals, if starter Calais Campbell's bad calf prevents him from playing Sunday.

"I figure the more depth, the more interchangeable parts you have, the better you will be," Horton said.

It's been a bumpy ride for Carter, who impressed as a sixth-round draft pick a year ago. He hasn't played much – just 68 defensive snaps thus far through nine games, a little more than 11 percent of the time – and part of that was difficulty in picking up his new spot.

"I'm feeling pretty good at end, now," Carter said. "I didn't like defensive end at first, I'm not going to lie. I hated it. Now, I like it."

The reasoning was simple. Carter, who hadn't played defensive end since his freshman year at UCLA, wasn't comfortable and wasn't making many plays. Not like he was used to at nose tackle, a position where he still says "my heart is there." Carter does have the build (6-foot-5, 300 pounds) that can work as a 3-4 end, however, and with Campbell's injury, the move looks even more fortuitous.

"We've moved him around some and in hindsight, that's good," Horton said. "Would I like for him to have had more snaps? Yes. But I am glad we moved him around."

Carter admitted playing end was "harder than I thought it was." Now he is the likely starter if Campbell is out. He dismissed the lack of playing time, saying he's learned a lot in practice.

"I'm ready to put up some good marks, some sacks, some tackles," Carter said. "I'm getting on the field. I can put some film up there, show everyone what I can do."

CAMPBELL LIMITED, WILL BE JUDGED SUNDAY

Campbell was limited Friday, and coach Ken Whisenhunt said the defensive end will get a pre-game workout to see if there is a chance he can play.

"We have a couple of guys we are going to work out on Sunday and he would fit into that," Whisenhunt said.

Quarterback Kevin Kolb, still dealing with his ribs injury, was the only Cardinal to sit out practice.

Horton not only could plug in a new defensive end but will definitely have to deal with a new starting linebacker, with Quentin Groves taking over for O'Brien Schofield after Schofield's season-ending ankle injury in Green Bay. Horton, however, said he wouldn't be changing much.

"I won't change a call," Horton said. "We'll be aggressive. I've been harping all year on our depth and this is where it plays in. I have confidence in whoever is playing."

INJURY UPDATE

Besides Campbell, the Cardinals have four others who are questionable after being limited Friday: cornerback Greg Toler (hamstring), cornerback Jamell Fleming (back) and tight end Todd Heap (knee).

For the Falcons, coach Mike Smith has already called wide receiver Julio Jones, battling a bad ankle, a game-day decision, as well as linebacker Sean Witherspoon. Neither player practiced all week. Also questionable for the Falcons after a limited Friday are defensive end John Abraham (back), running back Michael Turner (groin) and defensive tackle Vance Walker (ribs).

TOLER MANAGES FRUSTRATION

In college, at tiny Saint Paul's, Toler didn't get treatment. "I never had no trainers," he said. "I wasn't getting banged up then."

That's why it's been difficult for the cornerback, who had never been hurt before tearing up his knee last year and missing all of 2011. His return was ragged this season, and when he finally solidly got back into the lineup, he suffered a bad hamstring injury on a Rams' touchdown bomb Oct. 4 and has been struggling with it since.

"You just have to stay motivated, stay positive," Toler said. "It makes me emphasize technique. I'm athletic and you just want to go, but when you are hurt, you have to play your technique as good as possible. I don't think about rust. It's the communication with the guys I need to watch, but as far as rust? Nah."

Toler is hoping he will be ready for the Falcons Sunday, especially against a team that features two high-profile wideouts in Roddy White and Julio Jones. He said he wanted to be playing "yesterday."

"My body is just so up and down," Toler said. "I just miss (the game) so much. You just try not to get frustrated."