Jason Kelce has been around a long time, as least in NFL years. He's seen the Eagles at their best. He's seen them at their worst. He's watched as closely as anyone as his team has gone from champion to also-ran. There's been a need to blame one coach, one player, one scheme, just one thing for the Eagles' decline this season.

If only it were that simple.

"If I'm being honest, you wish that there was just one guy out there getting his tail kicked and grossly playing bad, because it would be as simple as putting somebody else in," Kelce said Wednesday. "The biggest thing that you see, in my opinion, this team [vs.] last year, at least offensively, is the cohesion, people being accountable to the job that they're asked to do, everybody being on the same page."

"Last year, it just seemed like everything was clicking, everybody."

The Eagles couldn't possibly bring everybody back. But they lost key players, in Kelce's estimation, who were valuable for how they prepared as much as how they played. The center wasn't pointing the finger at anyone for the departures. He understands as well as anyone that roster turnover is inevitable.

In most cases, it was hard to argue with the front office's decision to part with a certain player. But it doesn't change the fact that losing veterans such as tight end Brent Celek, wide receiver Torrey Smith and running back LeGarrette Blount, according to Kelce, and replacing them with new, younger faces, was going to affect the offensive consistency.

"If you look at last year, quite frankly, we were a different team," Kelce said. "A guy like Brent Celek, who was not only accountable for his position, but was a leader in the locker room and a guy that made sure that he had an aspect of what he had to know for the game time and he had been doing that for years and years and years.

"And then all of a sudden, you go, Zach [Ertz] is the veteran leader there, but you have a rookie [Dallas Goedert], you have another guy [Josh Perkins], has been playing a lot of time for us. But you got Trey Burton, who had been here for a long time. Now he's gone.

"The [running] backs have not had the amount of game experience that LeGarrette Blount had last year. Jay [Ajayi] has been hurt. Obviously, Corey [Clement] is the guy that's probably seen the most time out of all those guys. Torrey Smith was a guy who played a lot of football for a lot of different teams. I just think that there was a greater level of accountability from a cohesive standpoint of everybody working together."

Kelce didn't mean accountable in the sense that some players are shirking responsibility or that there's less physical effort. To the eight-year vet, accountability is going that extra step in preparation.

"It's making sure that going into the game you've rep'ed it in your mind if you haven't had the physical rep," Kelce said. "And this just isn't players — it's coaches; it's everybody. Everybody takes accountability in making sure that everybody's ready to go.

"From a player's standpoint, it's on you to make sure that you're watching the film, you're doing everything during the week necessary to improve, to make sure you understand the finer coaching points, every little detail, so that when you're in the middle of the game, you're not playing slow or apprehensive. You know exactly what you have to do, and you go 100 percent and you give great effort.

"And it's also on the coaches to make sure that all the guys are ready to go."

Injuries have played a part in the Eagles' struggles, Kelce noted. But it's just one piece of a large pie of problems. It's the whole team, to steal a phrase Kelce used for a much different reason just nine months ago.

Here's a closer look at Sunday's loss to the Cowboys and some of the issues plaguing the offense, whether it's game-planning and play-calling, execution, personnel, injuries, or all that:

First quarter

First-and-10

For their first play, the Eagles ran a little naked rollout. It was just one play, but it was unsuccessful and for a start that was scripted and conceivably practiced several times before the game, it's puzzling that two veterans didn't execute their jobs.

Ertz (No. 86) blocked defensive end DeMarcus Lawrence (No. 90), but he was supposed to shade him inside as Carson Wentz (No. 11) rolled right. But he held the block too long and disrupted his route as the safety valve.

Eagles offensive coordinator Mike Groh: Zach is part of the outlet plan there, but we want to try to get it contained there.

Down the field, receivers Alshon Jeffery (No. 17) and Nelson Agholor (No. 13) ran switch routes. Agholor had the option to run a "go" vs. zone defense on the outside, but he incorrectly read man coverage and cut off his route.

The Eagles left a potential six points on the field, and more yards than just one if Ertz had released earlier. The execution was faulty, but did Pederson, Groh and company put their players in the best scenarios to succeed? Did they coach the play up correctly?

Ertz: I've blocked that block 1,000 times. Obviously, [Lawrence] is a very special player. Best player on that defense. But I put a lot of pride in my blocking. It's not something that I just take for granted. I think the coaches trust me. I've been doing it for years now. We ran that same play against some really good players in Jacksonville and I stoned them every time.

Groh conceded that maybe having Ertz – a receiving tight end – block one of the best edge rushers in the NFL might not have been the way to go. But the Eagles have used an elite edge rusher's aggressiveness against himself – see: Von Miller last season – and that was likely the point of the first play.

Second-and-10

The second play from scrimmage was a toss left to running back Josh Adams (No. 33). After Ertz ran pre-snap motion to the right, linebacker Leighton Vander Eshe (No. 55) motioned to fellow linebacker Jaylon Smith (No. 54) that the play was going in the other direction.

If the Eagles execute the play, it shouldn't matter much, but Kelce didn't get over to Smith in time and Adams was held to no gain. Was the call too predictable?

Pederson: I go back and look at all their games and I see how they start that first series, that first drive, and try to put plays accordingly. Then I have to go back and look at how we started games by play call, play design, so that I'm not repeating and having any indicators there.

But execution, or lack thereof, was also a reason the play didn't work. Receiver Jordan Matthews (No. 80) couldn't sustain his block. Even then, Adams had an opportunity to cut back and gain some positive yards, but he didn't, for whatever the reason.

Third-and-9

A play later, newly acquired receiver Golden Tate (No. 19) finally took the field. The Eagles ran a play-action screen to the receiver. Nine yards is a lot to ask, even for Tate, who specializes in yards after catch, but left tackle Jason Peters (No. 71) didn't help matters when he couldn't shield Vander Esch.

Pederson: In the case of some of our struggles, it has just been, just our execution. Just sustaining a block or the read by the quarterback.

The Eagles have gone three and out in their opening drives in five of nine games. They've been just as bad the rest of the first quarter, and average a NFL-worst 2.3 points.

Groh: It's something that if it was one thing, it would be an easy fix. But it's a little bit of this, and a little bit of that.

It could be argued that Pederson needs to ditch the scripts and give Wentz more early freedom. The one time the Eagles put together a long, touchdown-scoring drive to open the game, it was up tempo vs. the Colts with Wentz able to make the calls at the line.

Wentz: We all have an idea that we all kind of add our input to. Coach is making the calls, obviously, but I've always trusted coach with when we're going that no-huddle-type stuff, up tempo and when we're huddle calling it. And every week's different.

Second quarter

Second-and-2

The Eagles have had an inordinate number of injuries. Injuries to tackle Lane Johnson, receiver Mike Wallace, Ajayi, and others have pushed many reserves into the lineup. The Eagles haven't used it as an excuse – and couldn't last year even though they had significant losses — but the depleted roster has obviously affected production.

Halapoulivaati Vaitai isn't as good as Johnson. Shelton Gibson isn't as good as Wallace. Wendell Smallwood isn't as good as Ajayi. Players like Kelce (knee) and Peters (bicep) have also been playing through injury. It happens more than outsiders realize, but it must be considered when evaluating performances.    

On this second and two rush, Peters' responsibility was to get to the second level. But he wasn't square and when he had to use his injured arm to hold off Vander Asch, he clearly couldn't and flopped to the ground in obvious pain.

Kelce: Offensive line-wise, we'd have guys injured, in and out of lineup.

Kelce hasn't missed many plays, but he hasn't been as mobile – as evidenced by the above block attempt on the Adams run – and the Eagles haven't had as many, and much success on, plays that utilize his athleticism.

Fourth-and-1

The combination of poor play calling, execution and injury came to a head on Pederson's second quarter gamble at the Cowboys 20. The Eagles had Adams run behind Vaitai. Lawrence drove him off and Tevin, who didn't bite on jet sweep action, and cornerback Jourdan Lewis cleaned up.

Vaitai: I just saw [Smith] was outside Lawrence and I knew he was going to go in. So me and Ertz were supposed to double team him to the backer. … It's just one of those things. DeMarcus Lawrence is really good.

Pederson: Offense was just designed to basically circle the defense, and only thing that kills the play is penetration.

Vaitai should be able to block that up, but on a crucial play was it worth taking that risk? Was it wise to place the onus on the little-used rookie tailback rather than have Wentz drop to throw or roll out with an option?

Groh: They made a good play on it.

You can tip your cap to the Cowboys, but the Eagles had only one yard to gain and instead lost three.

Third quarter

Third-and-7

All it takes sometimes is for a split-millisecond pause and the entire timing on a play can be thrown off. The Eagles had to settle for a field goal early in the third quarter after Wentz and Jeffery failed to hook up in the end zone.

Jeffery, lined up in the slot at the 8-yard line, ran a post. He hesitated, though, even though he was open vs. zone.

Groh: He was friendly right there in that window. … The defender [in the post] caused a little hesitation there, and I think that just threw off the timing just enough.

Wentz, in turn, hitched, and his pass was a touch too far ahead of Jeffery.

Wentz: The way they were playing coverage, we talked about it all week. The way they reacted on the field was a little differently. That is one where we are kicking ourselves and I want to have back and I just missed it.

Could Jeffery and Wentz have been better prepared vs. that look? It's difficult to say. But a touchdown was there to be had. The Eagles led the league in red zone conversions last season (65.5 percent), but this year that number has dropped to 55.9 pct. Missed opportunities have been one reason why.

Fourth quarter

Third-and-2

The Eagles, trailing 27-20, with two minutes left, had the ball at the Dallas 30. The Eagles called for a screen pass to Clement. The Cowboys were aggressive and rushed five defenders.

Pederson: We anticipated pressure and we got it.

But several things went wrong, at least from the Eagles' perspective. For one, Vander Esch stayed home and diagnosed the screen quickly.

Vander Esch: Well, I knew they were going to try something kind of nifty, I guess you could say. They tried that screen, so I knew that was coming.

Did the Eagles project the screen or did he just make a good play? Or did Kelce and guard Brandon Brooks err when they both tried to block Vander Esch? Clement still had the opportunity to cut back inside, but he didn't and was dropped for 5-yard loss.

Clement: If I could go back to that, the big difference would be if I could switch the ball I could get my stiff arm out there and reach out for two more yards. I put that on me. Anybody should be able to get two yards.

Groh: It was a bang-bang play, as a lot of screens are where you can get it started and get a chance for a big play. In this case, it didn't work out. They made a good play.

And the Eagles, a play later, came up short on fourth down, all but hammering a nail in their chances to comeback. It's been that kind of season.