The Redskins will face the Dallas Cowboys on Sunday in their final game of a terrible 2019 season.

Bill Callahan will coach that game, but afterward, all bets are off.

Who takes over that job as the Redskins next head coach, however, could be starting to take shape.

Multiple sources have told NBC Sports Washington that Marvin Lewis could be a top candidate. The former Bengals head coach is now an assistant at Arizona State University, but he has previous coaching experience with the Redskins as a defensive coordinator in 2002 and is said to have a solid relationship with Washington owner Dan Snyder and others in Ashburn.

It’s easy to knock Lewis’ lack of playoff success with the Bengals. He went to the playoffs seven times in Cincinnati and never won a game. That's almost hard to do and something that has dogged Lewis for years.

In Cincinnati, Lewis had to do much with little. The Bengals are a notoriously cheap organization and the owner serves as a de facto general manager. In his 16 seasons as head coach, Lewis won more than 50 percent of his games, with 10 wins or more six different times. The Redskins haven't won more than 10 games since 1991, and have only gotten 10 wins twice in the last two decades.

It's easy to forget too that Lewis was at the helm of an explosive Bengals team that won 11 games in 2005 and looked poised for a deep playoff run before Carson Palmer injured his knee in the Wild Card game.

In Washington just consistently getting to the playoffs would be a big step. It’s happened only twice in the last decade, and then only as a result of somewhat long shot late-season win streaks.

While the Redskins have grown more tight-fisted with cash under Allen’s leadership, Snyder is still a big spender. Last offseason the Redskins signed Landon Collins to one of the richest contracts ever signed by a safety and the team has a long history of not just paying in free agency, but over-paying. Lewis would be at the wheel of a much different type of vehicle in Ashburn than he had in Cincinnati.

It also might make sense for Washington to hire a head coach with a defensive focus. The team hasn’t done that since Marty Schottenheimer in 2001, and while the team has amassed some talent on the defensive side of the ball, the group has largely underperformed.

With Lewis’ track record, it would make sense to expect immediate defensive improvement. Before he took over the Bengals jobs in 2003, Lewis guided the Redskins to the fifth-best defense in the NFL in 2002, and prior to that was defensive coordinator for the Ravens during their first Super Bowl triumph.

Lewis isn't the only name to watch. Ron Rivera has also been reported as a possible candidate for the job.

Rivera has an even more impressive resume as a two-time Coach of the Year award winner. In nine years in Carolina, Rivera's teams went 76-63-1. In 2015 the Panthers went 15-1 and went all the way to the Super Bowl before falling to the Denver Broncos.

A linebacker for the famous Super Bowl-winning 1985 Chicago Bears, Rivera is an excellent defensive mind and has a reputation as one of the best people in the NFL. It’s an easy assumption that Rivera could also improve the Redskins defense.

Both Lewis and Rivera might choose to keep current Redskins offensive coordinator Kevin O’Connell on their staff. He made great strides working with rookie quarterback Dwayne Haskins this season, and it might be best to keep the pair working together.

Rivera will be the hotter coaching candidate, and that could hurt the Redskins, particularly if team president Bruce Allen sticks around. It's been reported that some coaching candidates are uncomfortable

With the current power structure at Redskins Park with Allen at the helm.

Mike McCarthy’s name has also been suggested as a fit in Washington. He’s an offensive coach with a Super Bowl ring, but reports of a sour relationship with Aaron Rodgers during their time together in Green Bay haven’t helped his resume. McCarthy will get plenty of looks this coaching cycle though, but sources say that hasn’t happened yet with Washington.

Current Chiefs offensive coordinator Eric Bieniemy is also a candidate for the gig. He's got a strong record with the explosive Kansas City offense and has Andy Reid pushing his candidacy as a top coaching candidate.

Sources have told NBC Sports Washington that team owner Dan Snyder has been working with a select group of football advisers to determine his next steps with the team and that Snyder wants to move quickly.

There's also the specter of Urban Meyer shadowing the Redskins coaching search. He took in a game with Snyder in the owner's box at FedEx Field a few weeks back, and has close relationships with Alex Smith, Terry McLaurin and Dwayne Haskins. Meyer coached all three during his various college coaching stops and is one of the hottest names on the coaching market.

Meyer has said that he would prefer to be a team executive in the NFL rather than a coach, and while Snyder's group of advisers does not include Allen, a source confirmed, it would be no surprise if Meyer has offered some advice.

The biggest question with the Redskins is not at head coach but rather Bruce Allen's future. Should he be removed or resign, when does that happen? If he stays, what coach will come to Washington? If he gets reassigned, what does that actually mean?

Those questions don’t have answers yet.

By Monday afternoon, things could look much different.

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