Vinny Curry had another quarterback sack on Sunday, and it was a perfect display of the player he is and the player the Eagles think he will always be.

The Dallas Cowboys faced third and 18 in the third quarter, and Tony Romo dropped back and stood there like he couldn't cross an intersection until the traffic light changed, and Curry started from the left and came after him, pushing into two Dallas offensive linemen before spinning around them, and kept coming until he got to Romo and hit him from behind and jarred the football from his hands.

It was Curry's ninth sack of the season. On the Eagles, only Connor Barwin, with 141/2, has more, and Barwin has played close to 600 more snaps this season than Curry has.

"That's just the best aspect of my game," Curry said Tuesday, "but for the most part I'm an all-around player."

He might think that, but the Eagles don't. They make sure that Curry, a third-year defensive end, does just one thing in their defense: chase quarterbacks. He has been on the field for 360 snaps this season, according to Pro Football Focus. Eagles opponents have called passes on 261 of those plays, and Curry has rushed the quarterback on all 261. Curry envisions himself as a Swiss Army knife. The Eagles look at him and see a single sharp blade.

"Vinny's been outstanding for us," defensive coordinator Bill Davis said Tuesday. "Do not misinterpret this. But we've got a lot of guys who are in on run downs. . . . We put Vinny in on very obvious passing situations and we try to make calls to help Vinny win and help our guys win. And he's doing a great job of getting those sacks. But if you increased his number, just increase the number of times he's playing the run - and he's getting better at that - his sack numbers, I don't think, would change."

Davis' assertion makes Curry an interesting case study to look at how the Eagles approach building a defense. Lots of teams have had pass-rushing specialists, and maybe Curry really is nothing more than another, albeit an excellent and productive one.

Davis and head coach Chip Kelly prefer to have their defense play a 3-4 alignment, and they have particular philosophies and physical requirements about the kinds of players who should line up at each position, and Curry fills a vital and dynamic role for them. In that regard, his situation is akin to that of Brandon Boykin, whom the Eagles consider to be so valuable as their slot cornerback - and too small to play on the outside - that they've resisted the suggestion to replace either Bradley Fletcher or Cary Williams with him.

So the Eagles don't mind if Curry is one-dimensional. Sacks are big plays, and he provides them.

"It's like hitting a three-point shot; it's a game-changer," said Curry, who played six games as a rookie and didn't record a sack, then had four sacks in 14 games last season. "The Philadelphia Eagles brought me in to get after the quarterback. The first year didn't go as planned. Second year was OK. In the third year, everybody's like, 'Oh.' "

And the Eagles can have the luxury of keeping Curry around at a reasonable price for his fourth year. Next season will be the final season of his modest rookie contract - the Eagles took him in the second round of the 2012 draft - and he will count just $1.08 million against the team's salary cap, according to the salary database Then he'll become a free agent.

If you're Curry, would you prefer to be a situational pass-rusher here or possibly an every-down player somewhere else?

"I would definitely be an every-down player, but it could be here, too," he said. "Nobody ever knows. Everybody who dreams about being in the NFL dreams about being an every-down player and a household name for their football team."

The question that Curry has to answer - for the Eagles and perhaps other teams, if not for himself - is whether he can develop enough to stay on the field more. He admitted that when the Eagles switched from a 4-3 scheme to a 3-4 upon Kelly's and Davis' arrivals, he struggled to adjust because he'd never played a 2-gap technique before. That is, he was accustomed to surging forward into one hole along the line of scrimmage and pursuing either a running back or the quarterback, instead of reading a play and reacting accordingly.

"Let's state the obvious there," he said.

But then, that's the conundrum for the Eagles. Why make a point of diversifying Curry's game when he's so good at what he does best? They'll need him in these final two games this season, against the Redskins and the Giants, to make sure Robert Griffin III and Eli Manning don't tear apart that Eagles secondary the same way Romo did. A man can make a fine living in the NFL as a terrific pass-rusher, and the Eagles seem to think that's all Curry will ever be. It's just that when he was told what Bill Davis said Tuesday, Vinny Curry listened and said, "I don't know about that. I don't know about that."