How good can Sam Bradford be?

Well, he's 28-years-old and has had two surgically repaired knees.

But he's only thrown one interception in the last four games for the Eagles, and has a better QB rating than Eli Manning in that span. He was the No. 1 overall pick when he was drafted, was the Rookie of the Year, and Cardinals head coach Bruce Arians has nothing but respect for the Eagles' emerging leader.

"As you're learning, you're playing slower," Arians, who has been very high on Bradford since his days at Oklahoma, said. "As you get a feel for it, the game slows down, and your athletic ability can take over, and Sam is blessed with a ton of athletic ability. I had him rated as one of the best ever to come out, and he just got unlucky with injuries. He looks like he's starting to flourish in that offense."

Chip Kelly agrees, even acknowledging that Bradford might be close to stepping his play up to the next level.

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"I think there's another level for everybody, so I don't think anybody has ever arrived at this game," Kelly told the media Wednesday. "And I think Sam will be the first to tell you the same thing that he has gotten better each week. I think he has a better understanding of what's going on. Kind of the game slows down for him. You can see him getting to different things, which puts him in a position where he can now get to the second, third, fourth option on some plays. He's doing a good job with a lot of things. As the season has gone along, we've given him more things to do and he has handled it extremely well. I don't think he's tapped out by any stretch of the imagination.

I think he continues to work at it. He has a great work ethic. He's not a big talker, but he's a big worker and he'll continue to work and get better and that's what we hope, that as we continue to get better as a team, that he'll continue to get better as a player."

In recent weeks, Bradford's comfort and knowledge of his teammates is what has propelled him to play better football. Eagles wideout Jordan Matthews sees the quarterback making better decisions, and ones based on his relationships with his players.

"I've seen his execution fuel his confidence," Matthews, who is nursing a back injury and was limited in Wednesday's practice, said. "He is getting more comfortable withe everybody. ... He's getting to know his personnel better he knows his guys. With [tight end Zach] Ertz he is putting those balls high and away to put Ertz in a good position to make plays. He is giving Josh [Huff] room to run. He is really feeding our strengths."