Sunday was up there as one of the toughest games to watch over the last few years if you are an Eagles fan. While the defense did everything it could to keep it close, the offense, as Chip Kelly put it was "pretty hard" to watch.

I know that fans of the team want to know what the issue is and how to fix it. Everyone wants that. After watching the game back (over and over and over again), it really was a complete team effort on the offensive side of the football. It starts up front in the run game. With the additions of DeMarco Murray and Ryan Mathews, the assumption was that this offense would continue to be focused on the ground attack, and it has yet to even be a serviceable way to move the ball thus far in 2015.

The Eagles ran the ball 16 times yesterday with their running backs. Murray had 14 carries (with one coming back because of a penalty), and both Mathews and Darren Sproles had a carry each. Of those 16 touches, the running back was hit at or before the line of scrimmage 11 times. The result? Just one run of more than 3 yards on the entire day. It doesn't matter how you draw it up on the whiteboard or how many wrinkles you add to your scheme, if you can't execute your blocks up front you're not going to be able to move the ball on the ground.

Chip Kelly tried numerous ways to get things going with the run game against Dallas. Whether it was the formation (25 percent of those 16 running plays came with the quarterback under center), the run scheme (Inside Zone, Outside Zone or Sweep), the placement of the running back (they ran both to and away from the the side where the running back lined up pre-snap) or the run strength (they also ran to and away from the tight end), the Eagles had tough sledding against the Cowboys. They tried to mix up their tendencies and tried to add wrinkles to what has worked in the past, but as Kelly said in his Monday press conference, it goes back to basic fundamentals. The Eagles just did not block well enough to win the game on Sunday.

Here is a play that was brought up at the press conference on Monday. Judging by the pre-snap alignment of the Cowboys, in a perfect world this is how you would draw up this inside zone run to the left. What this pre-snap screenshot does not account for, however, is movement by the defensive front.

With the defensive end looping inside into the B gap, there's a miscommunication in responsibilities here for Jason Peters and Allen Barbre.

The defensive end cuts inside, and Peters moves up to the second level, as does Barbre. With both linemen thinking that the other has the defensive end, Murray is brought down for a loss to bring up third-and-21.

Kelly mentioned multiple times since the end of the game that there simply was too much penetration in the backfield throughout the contest. It was a consistent theme, although the reasons for it changed throughout the game. Whether it was communication or just plain execution, the offensive line and tight ends will have to do a better job moving forward for the run game to improve against the New York Jets.

I mentioned some of the new wrinkles from the Eagles' run game, and how they tried some new things to get things rolling on the ground. Let me know show you an example of what I mean.

It's first-and-10 and Sproles lines up detached to the right on the hash mark.

Just before the snap, Sam Bradford brings Sproles into the backfield to run a version of their sweep play. On this iteration of the scheme, you see a pulling guard in Barbre and a lead blocker in the form of Mathews, who is lined up in the backfield to the left. Kelce is charged with getting to the second level, while Peters and tight end Brent Celek are responsible for down blocking the 3- and 6-techniques to that side.

Again, slants from the defensive line cause penetration up front. The 3-technique (defensive tackle lined up between Barbre and Peters) bangs into Jason Kelce, who is unable to get to the second level as a result of the contact. With Kelce unable to get up to the linebacker, Sean Lee has a free run at Sproles and brings him down for a 4-yard loss.

The sweep play, which has been a pretty reliable run for the Eagles over the last two years, had very little success against Dallas. By my count, the play was run four times for a combined total of -17 yards. It appears as if the Cowboys made it a point to try and hold Kelce up at the line of scrimmage and prevent him from releasing out into space to execute his job. I'm interested to see what the Eagles' staff does to counteract that moving forward, if that was indeed the case.

It wasn't just the run game for the Eagles, as the pass game had it's share of issues as well. Kelly mentioned Monday morning on SportsRadio WIP that he thought Bradford was "up and down." The protection wasn't always there as well. One of the big concerns, however, was the amount of drops against Dallas, a problem that carried over from the game against Atlanta.

This was a vertical route by Jordan Matthews that was open. Bradford put the ball where only he could get it. It was a tough catch, absolutely, but you'd like to see Matthews come away with this reception. It was a problem shared by the whole receiving corps. This is an issue that you'd like to see corrected this week against the Jets and their tough secondary.

A lot of the discussion after the game circulated around the interception by Bradford in the red zone. It came on a play that we've seen countless times from the Eagles. They've always had a ton of success with it, the shallow cross, or as those who are well-versed in the "Air Raid" offense call it, the "Mesh" play.

Before we get to the interception, however, let's look at a play from one series earlier.

It was second-and-10, and the Eagles called this play hoping the Cowboys were in man coverage.

Unfortunately, the Cowboys were in zone coverage. Bradford's options are limited, and he throws an incomplete pass. I wanted to show you this play though, so that you could see the end zone angle and see what Bradford saw.

Bradford is looking at the third crossing route from Matthews, who is settling down over the ball. As he looks to pull the trigger though, look at the Dallas defender with his eyes on the quarterback. Bradford sees that and eats the throw at the last second by throwing it in the dirt to live to play another down.

Fast forward to the next series. Down in the red zone, the Eagles run the same play. The Cowboys are in a slightly different defense with man principles, but have the play defended well. Bradford gets through his progressions and again settles on his target, the third crossing route settling over the ball. This time it's Zach Ertz.

When Bradford looks at Ertz, he sees Lee's back turned away from him. One thing you hear all around football as a rule for quarterbacks is "when you see the defender turn his back to you, pull the trigger." Bradford does that, Lee turns and the ball is picked off. It wasn't a perfect throw, but it wasn't the wrong decision for Bradford, who I'm sure would love to have that ball back.

Check back on Tuesday for my review of a strong Eagles defensive performance against Dallas.

Fran Duffy is the producer of "Eagles Game Plan" which can be seen on Saturdays during the season. Be sure to also check out the "Eagle Eye In The Sky" podcast on the Philadelphia Eagles podcast channel on iTunes. Prior to joining the Eagles in 2011, Duffy was the head video coordinator for the Temple University Football team under former head coach Al Golden. In that role, he spent thousands of hours shooting, logging and assisting with the breakdown of the All-22 film from the team's games, practices and opponents.