THIRD-AND-LONG was a huge part of the Eagles' loss to Seattle Sunday.

Overall, the Eagles converted two of 11 third downs, the Seahawks converted seven of 16. Faced with third and 6 yards or longer, the Eagles failed to convert all seven times they were in the situation, while the Seahawks converted five such scenarios; they were four of six in the first half.

The Eagles' third-down playcalling was very conservative, perhaps expressing Chip Kelly's limited faith in the skills of quarterback Mark Sanchez. Several times, the Eagles either ran the ball on third-and-long, or they threw short passes that seemed to have no chance of moving the sticks. Obviously, against the best defense in the NFL, third-and-long is a bad place to be.

In his day-after news conference, Kelly acknowledged that "nobody on offense played very well" in a benchmark game against the defending Super Bowl champions. Asked about throwing short of the first-down marker, Kelly indicated the Eagles thought their receivers could gain yards after the catch that just weren't there against Seattle's linebackers and secondary.

"Some were runaways, where you're hoping they beat the man-to-man coverage, and we uncover a little bit quicker and separate the way we need to separate, and run away from them a little bit," Kelly said.

The defensive third-and-longs have been a persistent problem, for a defense that really isn't that bad at getting off the field on third down overall (13th in the NFL coming out of the weekend, 38.5 percent.) On third-and-10 or longer, the Eagles ranked 29th, though.

Reuben Frank, of CSNPhilly.com, asked Kelly about the fact that the Birds have allowed eight conversions of at least third-and-15, two of them against the Seahawks.

"It's different games, but I think, obviously, [Seattle quarterback Russell] Wilson kept plays alive with his feet. He's obviously the most dynamic quarterback, keeping things alive, that we've faced so far this year. That was a big part of it," Kelly said.

"We talked about plastering in coverage when the quarterback is scrambling, but that's a long time to hold coverage if you're not getting to him . . . Normally, with another quarterback, you're getting to him, and in other games, those have been sacks for us."

Overall, Kelly said giving up a third-and-long conversion means you're doing the right thing on first and second downs, then "you're kind of letting them off the hook, so to speak. But it's a concern, and we need to clean that up if we're going to be a better football team."

Other highlights:

* Asked what he was told during conversations with officials about Seattle's defensive tactics downfield, Kelly said that all contact isn't prohibited, that the defender must impede the receiver. " 'Incidental' is the term they use," Kelly said.

* Kelly said the Eagles, with only 45 snaps, "certainly didn't run enough plays."

* Kelly indicated zone defenses are limiting the explosive plays Riley Cooper is capable of making. He again vigorously defended Cooper, whose 46 catches, Kelly noted, are one short of his total in 2013. But Cooper has 470 yards and one touchdown, vs. 835 and eight a year ago.

* Kelly said that he spent time with LeSean McCoy Friday evening, after the unexpected auto accident death of a cousin McCoy was close to, that McCoy took part in Saturday's practice and "expressed to us he really wanted to play." Later, on his 94WIP radio show, McCoy said breaking Wilbert Montgomery's franchise rushing yardage record Sunday was "something special," but he said he hasn't "really gotten a chance to really just feel it yet. There's a lot going on." McCoy said he needs to "get back into it [practice today] to really feel that type of accomplishment. This was a bad, bad game. I haven't really had a chance to digest it, and all that."

* Kelly said he thought his receivers were "hot and cold" against Seattle's press coverage. He said after seeing Richard Sherman in person, he agrees that Sherman certainly is really good.

* Kelly said he has gotten no update on quarterback Nick Foles' healing collarbone. A source close to the situation said Foles will get another scan after the Dallas game this weekend.

* Kelly said defenses have adjusted to limit the impact of Darren Sproles.

* Kelly said he thought cornerback Bradley Fletcher "was playing the ball the right way, from what we saw on the coaches' film" when Fletcher was flagged for a 44-yard pass interference penalty, the longest gain of the day for either team, which set up a Seattle touchdown. Seahawks receiver Doug Baldwin said after the game that he ran into Fletcher to try to draw a penalty.

* In a similar vein, Kelly was asked about a Seattle completion when TV caught Kelly imploring officials for a flag on Seahawks guard James Carpenter, who drifted about 20 yards downfield as Wilson scrambled. "It happens," Kelly said. "I made bad calls yesterday, too. It's just part of the game."

* Kelly said that while the focus is on preparing for Dallas, the team knows the playoff situation. With conference losses to Arizona, San Francisco, Green Bay and Seattle, the Eagles are unlikely to win a wild-card berth. They need to beat Dallas and win the NFC East.

* Kelly said he relies on the maturity of his players in bouncing back from a loss. "I just think they understand it - it doesn't define them . . . You have to answer to yourself. You know how well you played, you know how you performed on a given day. You're going to have days when you're really successful. We've had days like that. You're going to have days it doesn't work out the way you want it to work out. You're not going to pack your bags after that, take your ball and go home. I don't think we have a group like that. This team's got good resolve. I expect 'em to be flying high when we get in here tomorrow, get ready to go. There's no better thing to get their attention than playing the Dallas Cowboys at home, in the Linc, in front of our crowd."

On Twitter: @LesBowen

Blog: ph.ly/Eagletarian