Every time the Philadelphia Eagles' offense struggles, we hear the same narrative.

Chip Kelly's "college system" can't work on Sundays. NFL defenses are too sophisticated for some playground offense.

These are canned responses, uncontested layups for analysts and fans when something -- anything -- goes wrong with Chip and the Eagles.

And yes, it's true: Philly's offense is a bit of a mess right now. The Eagles rank 32nd in Total QBR, 29th in third-down conversion rate, 26th in yards per play and 16th in points per game. That's not what anyone -- Kelly included -- was expecting near the halfway point of the season.

But Kelly's "system" isn't the main culprit for the Eagles' struggles. For one thing, his scheme, though it's played at a breakneck speed and presented with plenty of window dressing, isn't all that different from the football we watch across the league on Sundays. Packaged plays? Aaron Rodgers runs those. The run game? Buck Sweep is the old Vince Lombardi power toss scheme. And those zone runs can be found at every level of the game. Sure, the Eagles like to operate out of the shotgun. Great, so does Tom Brady. He likes tempo too. And the Patriots play just as fast as Kelly's Eagles.

Here's the rub: Whether we are talking about the Eagles or small-town high school ball, it always comes down to players first, scheme second. (Chip The GM, of course, handpicked many of his players during the offseason. You want to throw the head coach into the fire? That's where you do it.)

The Chip Kelly-Sam Bradford marriage is off to a rocky start with the Eagles sitting at 3-4. AP Photo/Michael Perez

It starts, as always, with the quarterback. I get the appeal of Sam Bradford. He's a former No. 1 overall pick known for accurate passing and getting the ball out quickly. That's what Kelly wants. The Eagles expected Bradford to be an upgrade over Nick Foles -- why else would they give the Rams a better array of draft picks as part of their offseason trade?

While it's still too early to call the Bradford-for-Foles trade a failure, it's hard to ignore how tentative Bradford has played. It's almost like he's nervous. And perhaps worse for Philly, he offers no threat to run the ball. None. Why would any defender on the edge even begin to honor Bradford as a quarterback who can pull ball on the zone-read? Even Foles gave the Eagles a little something there.

And where is that quarterback who was supposed to challenge opposing secondaries with accurate passes downfield? Bradford ranks 24th in air yards per attempt (how far each pass travels) and 21st in completion percentage. That's a low risk-low reward combination that won't work in any offense, which is why he has thrown just 1.29 touchdowns per game (tied for 27th in the NFL).

Talking with a defensive coach this week, he described Bradford as "gun-shy." Is that fair? I think it is when you watch the tape. This is a player who has had two knee reconstructions and offers very little in terms of mobility inside or outside of the pocket. Does he scare opposing defenses? I doubt it. Go after him. That would be my plan.

Now, I can't put this all in the quarterback's lap, despite his below-average play. This past Sunday night -- when the Eagles scored just 16 points and averaged 4.31 yards per play against the Panthers -- showed us that Philly lacks playmakers at wide receiver. Look at the drops (16 this season, second most in the league). Look at the shocking second-year regression from Jordan Matthews (1 TD in seven games). Look at 31-year-old Miles Austin playing a prominent role.

"Whether we are talking about the Eagles or small-town high school ball, it always comes down to players first, scheme second."

And remember: Kelly let Jeremy Maclin walk this offseason. The receiver took more money in Kansas City, and his replacement, first-round pick Nelson Agholor out of USC, has been a ghost. In five games, the rookie has only eight receptions (on 17 targets) for 105 yards and he hasn't reached the end zone. That's not going to cut it.

Ironically, the position with the most stability is the one that had everyone all up in arms this offseason. LeSean McCoy is a good running back, an electric talent at times, but DeMarco Murray, Ryan Mathews and Darren Sproles can carry the rock in this system when they have the big boys up front putting in work.

And while the Eagles' offensive line has graded out as the No. 1 unit in terms of pass-protection rate, its up-and-down performance in the run game hasn't helped take the pressure off Bradford and an overwhelmed WR corps.

If you still want to blame the Eagles' backward slide this season on Kelly's playbook, then go ahead. Join the crowd. That's the narrative, right? But it's really about the lack of execution on offense within the system. You better have the guys to run that offense. And right now, I'm not sure Chip does.

ESPN.com NFL analyst Matt Bowen played seven seasons in the NFL.