As sudden as Sean McDermott's firing by the Eagles may have seemed, the defensive coordinator was put on watch as far back as the end of the 2009 season, team sources said.

When the defense came up short against Minnesota in December and again in the playoff loss to Green Bay, McDermott's days were numbered. But, in truth, the 36-year-old coordinator was on shaky ground after his unit allowed an average of 27.2 points in the final five games of the 2009 season.

McDermott was thrust into the position at the start of training camp in 2009, before defensive coordinator Jim Johnson's death. McDermott dealt with a number of significant injuries to players, and that bought him time after the two lopsided losses to Dallas that ended the 2009 campaign.

But changes were made before the 2010 season, one of which was the hiring of Dick Jauron as senior assistant and defensive backs coach. Another was coach Andy Reid's becoming more involved with the defense during practices, Eagles safety Quintin Mikell said Sunday.

McDermott's defense, though, got off to a rough start and allowed 59 points in the first two games before a spate of injuries. Reid and the Eagles' brass were frustrated, according to team sources, and from that point on, McDermott was under the gun.

The defense had its ups and downs the rest of the way, but as McDermott increasingly became a target for bloodthirsty Eagles fans, there were more low moments than high. He began to lose the support of several players, some of whom complained about their roles and others who thought McDermott's game plans were too complex.

"That's one of the things I have heard," said Mikell, one of McDermott's staunchest supporters. "Everybody's a different type of player. There were schemes he put us in that had the simplest tasks and we messed up. And there were complex things that we did right."

Trent Cole, who could not be reached for comment, told reporters earlier this season that he did not like McDermott's zone-blitzing schemes, which required the defensive end to sometimes drop back into pass coverage.

"There's nothing wrong with that," Mikell said. "Trent, he was coming from a good place. He just wanted to get to the quarterback and he didn't want to drop."

When Reid conducted exit interviews with the players a day after the Green Bay loss, one or two defensive starters told the coach that McDermott should go, team sources said. Mikell said that he and Reid had not spoken directly about his coordinator during his exit interview.

"Not that it would have mattered coming from me," Mikell said, "in light of my situation and whether I'm coming back or not."

Mikell's contract is expiring, but he said he wants to return to the Eagles. If he does, he'll be playing under a new coordinator. Mikell said that he had not spoken to McDermott.

McDermott, who has interviewed for vacant defensive-coordinator positions in Carolina and Denver, has not been available for comment.

He certainly had to explain this season to both teams. Early on, there were fourth-quarter meltdowns that culminated in an embarrassing defeat at Tennessee in which the Titans scored 28 points in the final quarter.

Then there was the Chicago loss, in which the Eagles allowed the Bears to score three touchdowns on four trips inside the red zone. That ratio was actually below the 76.7 percentage the Eagles had for the season, which was the worst in the NFL in 22 years.

McDermott, always a fiddler, began scheming radical ways to stop offenses. For instance, against the New York Giants in December, he unveiled a third-down look that had no linebackers and seven defensive backs on the field.

"Going into that week, I thought that was a good idea," Mikell said. "It looked like something that would work against [Giants quarterback Eli Manning]. But it didn't, although we did eventually adjust."

In the end, following in the footsteps of Johnson weighed heavily on McDermott.

"I've always been in his corner," Mikell said. "Obviously there were things he would have liked to have gotten better at. And when things don't go well, that falls on the defensive coordinator. But we have to take ownership for this, too."