Roseman had admired Washburn's success with the Titans and was initially sold on the idea by Washburn's agent, Tony Agnone, who had a strong working relationship with the GM, according to one source.
The proposal was initially met with skepticism. Reid, though, became convinced. The Eagles coach had become less familiar with assistants around the league and which ones were available and had come to rely on others for suggestions, one source said.
Reid, as he would with any decision after he consulted those around him, could either reject Roseman's proposal or adopt it. He chose the latter - an indication of how much Roseman's influence within the organization had grown after just one year as GM.
When asked if the decision to hire Washburn was his and his alone, Reid said Monday that it was.
The Eagles later issued statements from Reid, Roseman and owner Jeffrey Lurie, who has not spoken publicly about the team this season, reiterating that Reid has final say on football matters.
"Andy Reid has full and final control over all decisions over his coaching staff," Roseman said in a statement. "To say that I had more to say, or more involvement or more input that Andy Reid in hiring Jim Washburn is categorically false."
Reid fired Washburn early Monday morning, a day after the 3-9 Eagles fell to the Dallas Cowboys, 38-33, for their eighth straight loss.
Reid said that he had been considering the move for some time. Washburn was a divisive figure within the Eagles coaching staff and had become disruptive and threatened to quit when defensive end Jason Babin was released last week.
"That didn't quite work the way I wanted it to work," Reid said of hiring Washburn.
Washburn's personality never meshed with Reid's. Looking back, it was a peculiar move, not only because Reid went outside his staff - he typically promoted from within - but because of the timing.
Reid fired Sean McDermott as defensive coordinator less than a week after the Eagles lost to the Packers in the 2011 playoffs. Reports surfaced less than a week after that that the Eagles were in talks with Washburn. Titans coach Jeff Fisher had been fired, and Washburn's contract was up.
The Eagles had to work fast because many teams wanted Washburn. Roseman initially contacted the coach about going to Philadelphia, and then he negotiated a reported three-year deal with Agnone.
(Agnone represents some of the top defensive linemen around the NFL, including Babin and Eagles defensive end Trent Cole. Babin followed Washburn from Tennessee and signed a five-year, $28 million contract with the Eagles in July 2011. Cole and the Eagles agreed to a four-year extension in March.)
Reid, meanwhile, continued to interview defensive coordinator candidates. Several either turned down offers or made it clear they weren't interested, presumably because they would have the wide nine forced upon them.
Reid then looked inward and made the controversial decision to promote Juan Castillo from offensive line coach to defensive coordinator. To make the switch possible, he needed a replacement for Castillo. Reid had always respected Howard Mudd and was able to lure him out of retirement.
The addition of Mudd was another indication that Reid was less familiar with the younger generation of promising assistants. When he became the Eagles' head coach in 1999, Reid had a list of assistants whom he wanted on his staff, and he went out and hired them.
But as many of his top assistants left for other jobs, Reid had less success finding their replacements. Rather than look outside, he often promoted from within, and the results were often unsatisfactory. (See: Rory Segrest, defensive line coach, 2009-10).
That's where Roseman came in. He had gotten to know or was familiar with many of the top young assistants from the college and pro ranks. Except the coach he had in mind to replace Segrest wasn't young or in the mold of Reid's typical hardworking, steadfast assistants.
In the end, the choice of Washburn was a disaster for all parties involved.
Contact Jeff McLane at email@example.com or on Twitter @Jeff_McLane.