A euphoric Eagles locker room buzzed in the minutes before midnight on Sept. 30. The Eagles had just won their third game in four weeks, this time after the Giants missed consecutive field goals in a victory that gave the Eagles the lead in the NFC East.

In a make-or-break season for Andy Reid, the auspicious first month raised optimism in the NovaCare Complex. Players sounded confident. Coaches appeared relieved. The problems that were apparent even in wins - turnovers and injuries, specifically - were mere obstacles to be rectified.

"At that point in time," Giants wide receiver Victor Cruz remembered last week, "I thought they were definitely the team to beat."

They've become the team that's been beat. The Eagles did not win again until Dec. 9, and they have not won since. After the last Giants game, they were 3-1. Entering their second Giants game, the Eagles are 4-11.

"Three and one," wide receiver Jeremy Maclin said. "Everything kind of went downhill from there."

It went downhill in an embarrassing collapse that will include carnage that makes what happens on Monday far more interesting than what occurs Sunday, which is expected to be Reid's final game with the organization.

When players in the locker room tried to dissect what happened in 2012, there were too many issues to mention and not enough interest in rehashing all of them.

The Eagles have committed 36 turnovers, the most in the NFL. Only six players in their opening day starting lineup have lasted the entire season. Two in-season coaching changes were made.

"You don't get to being 4-11 by one thing," cornerback Brandon Hughes said.

But there were benchmarks during the year when players started to sense the season could be in trouble. Most of the damage occurred between a last-second loss to the Pittsburgh Steelers on Oct. 7 and a blowout loss to the Washington Redskins on Nov. 18, a downward spiral that made the season that once appeared so promising become so bleak.

"The momentum just kept going backward for us. I guess they call that a snowball effect," cornerback Nnamdi Asomugha said. "It was building, it was building, up until that point when we played Washington. That was a head-scratcher moment, like, 'Have we really gotten to this point?' "

OCT. 7-OCT. 14: Two last second-losses

The Eagles' first three wins came by a combined four points, and each required a fourth-quarter comeback. Winning close games was taken to be part of a character they had developed after underachieving in 2011.

Yet problems started to fester against the Steelers, particularly on a 14-play drive that resulted in a game-winning field goal. Pittsburgh converted two critical third downs, including a third and 12.

"That would have put us at 4-1," safety Kurt Coleman said. "Not to say that messed up our whole season, because we've had chance after chance to win games, but we've shot ourselves in the foot."

That was clear one week later, when the Eagles surrendered a 10-point, fourth-quarter lead to lose in overtime to the Detroit Lions. The final minutes were marked by defensive breakdowns.

"We were up 10 points, and we had a chance to get back to winning," defensive tackle Cullen Jenkins said. "We would have gone into the bye week at 4-2, and had a chance to get momentum back on our side. I think Detroit might have been the turning point."

When Reid was asked last week what changed throughout the season, he cited the inability to close games after demonstrating that trend early in the season. The Eagles fell to .500 entering the bye week and change was on the way.

"Whatever your record is, you're not out of it," Asomugha said. "Way too early."

OCT 16-NOV. 5: Castillo fired, defense fails to improve

Two days after the Lions loss, Reid dismissed defensive coordinator Juan Castillo, a loyal lieutenant put in an untenable situation. Todd Bowles replaced Castillo, and the hope was that the change in leadership could jump-start a lackluster defense that suddenly struggled to close games.

"Coming out of the bye, we knew we had to win," tight end Brent Celek said. "We had to turn things around, and we didn't do it. Just flat out didn't do it."

The Eagles lost their next two games to NFC South teams by a combined score of 58-20. The first came after the bye week, a game Reid had never lost in his 13 previous seasons as head coach. Yet the Atlanta Falcons dominated the Eagles, and Bowles' defense played worse than Castillo's.

The Saints offense continued the trend on Monday Night Football the next week. The defense looked confused, and quarterback Michael Vick still struggled with turnovers.

"Eventually it's going to get you beat," wide receiver Jason Avant said of turnovers. "It's one of those things that I thought, if we continue this behavior, it's going to lead to it. But you never ever think it's going to happen to you."

NOV. 11-NOV. 18 - Down in the division, down for the count

After losing to the Saints and slumping to 3-5, the Eagles still hung their hopes on the division. Five NFC East games remained, with the first coming at home against the Dallas Cowboys.

"As the season went on, I felt, just get one, get one, and we'll go on a roll," Maclin said.

In the loss to the Cowboys Vick suffered a concussion, putting the spotlight on Nick Foles for the first time since the preseason. Foles could not save the Eagles in a game swung by a Cowboys punt return for a touchdown.

The loss that signaled trouble to many players came Nov. 18 against the Washington Redskins. Both teams entered the game 3-6. Foles made his first start.

It turned into the Eagles' worst performance of the season. Washington's 31-6 victory sparked a winning streak that has not stopped. The Redskins play this Sunday with a chance to win the division, and there was a sentiment that the Eagles could have generated similar momentum if they had won that day.

Instead, Redskins quarterback Robert Griffin III completed 14 of 15 passes for 204 yards and two touchdowns, Foles threw two interceptions, LeSean McCoy suffered a concussion, and the Eagles fell to 3-7.

"We thought we were going to come in and kick their ass, honestly," Hughes said. "Then they come in and throw 14 for 15, another 200 yards? That was the moment where it was like, '[Shoot], we got to get something fixed, and we got to get it fixed fast.' "

NOV. 26-DEC. 30 - Playing out the string

The season continued to sink, with lowlights reading like a football rap sheet: Defensive line coach Jim Washburn was dismissed hours after a loss to the Cowboys; three turnovers in four plays in a loss to the Bengals; an intentional grounding to end the second loss to the Redskins. Outside of Foles' game-winning touchdown pass Dec. 9 against Tampa Bay, the Eagles have not experienced a winning locker room since the last night in September.

Different players offered different theories about why the losing occurred (injuries, turnovers, defensive miscues) and when the season soured (Detroit, Atlanta, Washington). But the consensus is that a team that each player was convinced would be a contender after the first Giants game enters Sunday's game with the reality that the season is spoiled, and changes are likely on the way.

"It [stinks]. It honestly [stinks]," Celek said. "Just because we did have high expectations going into the season. We've got a lot of talent, still got a lot of talent on this team. We didn't live up to it."

Contact Zach Berman at zberman@phillynews.com. Follow on Twitter @ZBerm.