A big concern for the Eagles this weekend is figuring out exactly when Cam Newton is a passer and when he's a runner.
With Newton, there's often no clear line. He runs when it looks like he's going to throw, and he throws when it looks like he's going to run.
This makes him more dangerous than ever because the way officials are calling hits on quarterbacks, the Eagles' defenders have to be very careful how and when they hit Newton, even when it looks like he's going to take off scrambling.
Because the officials will still protect him as a quarterback until he's beyond the line of scrimmage and clearly established as a runner.
"It certainly makes it difficult," defensive coordinator Jim Schwartz said. "When he's sitting there like this (assumes QB stance), he's still a runner. He's protected like a passer, but he can run at any time, not just when he's out of the pocket. They have designed runs that are almost Wildcat-type plays. He's taken direct snap and running quarterback power and quarterback counter and things like that. If he's in a passing posture, he gets protection. If he's running, then he doesn't, but, again, sometimes you have a hard time deciphering between the two."
Newton has 4,528 rushing yards since entering the NFL in 2011, third-most in NFL history among quarterbacks behind two former Eagles — Michael Vick (6,109) and Randall Cunningham (4,928).
New Panthers offensive coordinator Norv Turner has incorporated Newton's running ability into the Carolina offense more than ever, to the point that Newton, at 29 years old, is on pace for a career high in rushing attempts.
And while most running quarterbacks slow down as they get older, Newton is on pace for 666 rushing yards this year, which would be his second-most since 2012.
"Cam Newton has opened up every design run that you can imagine," Schwartz said. "They've really ramped up their designed quarterback runs this year over anything they've done in the past."
Schwartz spoke about what makes the Panthers' running game with Newton so dangerous.
Probably their willingness to do it in all down and distances and all field positions. There's a lot of teams that will run zone read stuff in the red zone or on a short yardage play. But Carolina, I don't think you can put any kind of constraint on down and distance. Third-down and whatever, you still got to handle the quarterback's designed runs, 2nd-and-20. I think (Sunday vs. the Redskins) they had 2nd-and-17 or 2nd-and-20, and they ran the quarterback. There's a lot of other teams you can take him off your radar in those situations. Not in this game. Every time that ball is snapped, whether it's a designed run or just an off-schedule scramble, we're going to have to account for him.
Newton is throwing the football better than ever, too. He's hitting on 66 percent of his passes — far over his career average of 59 percent — with nine TDs and four interceptions.
The Eagles have done OK against running quarterbacks, although they did allow Andrew Luck — a non-running QB — a career-long 33-yard scramble earlier this year.
Newton ran for 71 yards against the Eagles last year in Charlotte although he also threw three interceptions, and the Eagles won 28-23.
Newton has faced all 31 teams other than the Panthers in his career and his lowest passer rating is against the Eagles at 69.4.
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