The Eagles announced that defensive line coach Jim Washburn had been relieved of his duties and was replaced with former assistant Tommy Brasher on Monday morning.

Washburn had become a "cancer" around the team, according to one Eagles source, and had become increasingly difficult to work with after the release of defensive end Jason Babin last week.

Washburn had threatened to quit after his protégé was cut, the source said. Andy Reid beat him to the punch and fired him with four games remaining.

"This was a move that I made. Nobody else made this move. That's important for you to understand," Reid said during his Monday news conference, a day after the Eagles fell to 3-9 with a 38-33 loss to the Cowboys. "This isn't a move to save my job. That's not what this is. This is a move that I think needed to be done now."

Reid confirmed that Washburn's wide-nine scheme would essentially no longer be used by the Eagles.

Brasher was Reid's defensive line coach from 1999-2005. He and Jim Johnson, then the defensive coordinator, worked in unison to create a defense that was among the best in franchise history.

Washburn had started to alienate himself from the rest of the Eagles coaching staff as early as last season, not long after he was hired in January 2011, the source said. His abrasive and confrontational personality had rubbed many coaches the wrong way, especially those that were used to the professional environment Reid had fostered in his previous 12 seasons, the source said.

The culture clash came to a boil when Washburn tried to push Marty Mornhinweg's buttons on the sideline during a game in late November last season, and the offensive coordinator did not back down. The two had to be separated by players.

Washburn also didn't hide his disdain for former defensive coordinator Juan Castillo and would occasionally refer to him as "Juanita" in front of him and to his players, team sources said, confirming a CSNPhilly.com report.

Reid made several attempts to break up the frat boy mentality Washburn had brought to the defensive line. Washburn's meeting room had become a dorm room of sorts, and Reid had a refrigerator and coffee machine removed during the bye week.

"I would just tell you that there were things that I was disappointed in, and as time went on . . . I just thought it was the right thing to do," Reid said.

Washburn's agent, Tony Agnone, said that his client would have no comment.

The hiring of Washburn was a controversial move for Reid, who had just fired defensive coordinator Sean McDermott. Washburn was brought aboard before Reid had even named McDermott's replacement.

The Eagles coach wanted to improve his pass rush and said that Washburn's scheme would be the vehicle to pressure quarterbacks.

But the system dictated much of what the defense could do, and after several candidates turned down offers to become the coordinator, Reid promoted offensive line coach Castillo.

Washburn's unit produced sacks in his first season. The defensive line accounted for 46 of the team's league-high 50 sacks with Babin (18) and Trent Cole (11) leading the way.

But the pass-rush-first mentality up front and the wide gaps along the line placed additional run-stopping stress on the Eagles' below-average linebackers and safeties. The defense showed improvement in the final four games last season, but those wins ended up being "fool's gold," in owner Jeffrey Lurie's words after the season. Opposing offenses designed ways to keep Babin and Cole in check for most of this season, and Washburn's line no longer got consistent pressure.

With upgrades at linebacker, though, the Eagles became better against the run, and the secondary was stingy in the first six games. But after a fourth-quarter collapse against the Lions, Reid fired Castillo.

He replaced him with defensive backs coach Todd Bowles, and the switch blew up in Reid's face. Bowles said initially that he was keeping the wide nine, but he started to make minor changes to the scheme each week.

Against the Redskins on Nov. 18, several linemen were told to "read" either run or pass rather than rush straight for the quarterback. When Babin and Cole were asked about the alteration after the game, they both answered, "Ask Coach Wash."

While Washburn had been voicing his frustrations with Castillo's play-calling to his players for a year and a half, he had also become critical of Bowles, team sources said.

When Babin was waived last Tuesday, Washburn was livid, team sources said. Reid said that Washburn was alright with the decision, but the coach confirmed that firing Washburn "was something that I had been pondering and working through."

"I feel like that hurt [Washburn] a little bit," defensive end Brandon Graham said of Babin's release. "From what I heard, he didn't know that they were releasing him until he was actually gone. I know that was one of his guys. . . . I do think it got to him."

With Babin gone, the line got off to a strong start against the Cowboys on Sunday night. Graham, Babin's replacement, recorded 11/2 of the Eagles' two sacks in the first half. But there was little pressure on Tony Romo in the second half and the Dallas quarterback picked the Eagles secondary apart.

When the Eagles locker room finally opened after the game, several defensive linemen were huddled whispering as if something had just happened. A few exchanged foreboding looks.

Several hours later, it was clear what had happened or was about to happen: Washburn was gone. The team announced the move and said Brasher would come out of retirement at 6 a.m. Monday morning.

With Reid likely to be fired at the end of the season, Brasher could be the only coach on defense to have been with the Eagles for both the beginning and the end of the Reid era.

Contact Jeff McLane at jmclane@phillynews.com or on Twitter @Jeff_McLane.