Sam Bradford did not play well against the Cowboys on Sunday. He wasn't the main problem. He also wasn't the solution. But his interception to Sean Lee was emblematic of a larger issue that goes beyond the quarterback.

The Eagles trailed the Cowboys, 13-0, midway through the third quarter, but they had an opportunity to narrow the lead to six when the offense advanced inside the Dallas 5-yard line.

On second down, Chip Kelly slowed the tempo as he substituted different personnel. The Eagles coach called a play that was similar to one Bradford had success with under comparable circumstances in the preseason game against the Packers.

It called for a simple "mesh concept" in which two receivers run shallow crossing routes in opposite directions. It can also be known as a "rub" route because the receivers will sometimes cross each other close enough to rub shoulders. Some teams have the players practice by slapping hands. The Eagles have actually done this in games.

In Green Bay, Riley Cooper and Trey Burton were the receivers and Bradford hit the latter for a touchdown on fourth down. Against the Cowboys, Brent Celek and Josh Huff were the receivers. The play is designed to take advantage of man-to-man defense because the defender covering the primary target can be "picked" out of the play.

After the Eagles sent in new players, Dallas matched their personnel. With the play clock ticking down, Bradford surveyed the defense. It was unclear if he noticed that the Cowboys were going zone rather than man.

"We were calling a play trying to get some man coverage," Bradford said after the game, "and they zoned it off."

There were only six seconds left on the play clock when the ball was snapped, but even if Bradford had wanted to check into a better play against the zone, he didn't have an audible option.

Kelly said last week that his quarterbacks can audible, but former Eagles like Michael Vick and Matt Barkley have said they do not have that capability. They can change protections, although center Jason Kelce handles most of those chores.

Typically, Kelly's offense is going so fast that the quarterback doesn't have time to change the play pre-snap. The call is the coach's, and even if the clock were to drain down, Bradford doesn't have the option to check into a new play - a la Peyton Manning, Tom Brady, Tony Romo, most other quarterbacks, or as he did in St. Louis.

When the Cowboys rushed only four it was clear that they were dropping seven into a zone. Against the Packers, the defense blitzed and the play worked when Bradford stood in and delivered a strike to Burton. A few weeks later, Huff had some space, but he had two sets of eyeballs on him. So Bradford went to Zach Ertz in the back of the end zone.

And this is where the Bradford-not-playing-well part comes in. Ertz was covered. Lee might have had his back to the quarterback, but the throw either wasn't wide enough away from the linebacker so that Ertz could get it or it should have never been thrown.

"When I got back to Ertz," Bradford said, "it looked like Sean Lee had his back turned to him so I gave him a chance and somehow I threw it to him and he made a great play."

Bradford didn't make one great play on Sunday. Of his first 31 passes - minus the meaningless final drive - 15 were completed. All but two were either designed screen passes or short check downs. He once dumped to Darren Sproles rather than throw to an open Celek on a seam route.

When he did throw downfield, the results were often poor. Bradford was either off target or his receivers couldn't hang onto the ball. He was too high to Ertz and behind Nelson Agholor twice. Jordan Matthews dropped two passes, and Miles Austin, Cooper and Ertz each dropped one apiece.

Bradford has taken only five shots beyond 20 yards downfield in two games. But the run game inefficiency has allowed defenses to keep 1-2 safeties deep, especially with the Eagles so often in third down and long.

"When you go three and out, three and out, three and out, and you're not converting on third down or you're not giving yourself a chance to convert on third down because you're on third and long, it's just tough," Bradford said.

After two games, one in which he was pinpoint accurate for a half, it's not yet time to declare Bradford a bust. Both he and Kelly didn't make any excuses about rust after his two-year layoff. An argument could be made that he didn't play enough in the preseason, though.

"He was as sharp as anybody in how he threw the ball in the preseason," Kelly said on Monday. "But we are not doing that right now. Some of that is drops, some of that is protection, some of that is Sam. It's a combination of all three."

Kelly said that he remained "confident in Sam." It would be too early to make a change with backup Mark Sanchez, especially when there are problems across the board. But sometimes when there are potential problems, Bradford simply doesn't have the freedom to get out of them pre-snap.

"I think it is fixable," Bradford said of his struggles. "I don't think it is anything major."

jmclane@phillynews.com @Jeff_McLane