The task for Washington is simple. Beat the 4-10-1 Eagles and Washington is in the playoffs. 
Washington has a top-five defense, but a weak offense with injuries to its best skill position players. So a conservative game plan of playing not to lose is justified in this instance for Washington. 
Jalen Hurts has been an improvement on shell-shocked Carson Wentz. Opponents, though, by now have plenty of game film on Hurts. He remains largely untested as a passer. The Eagles are going to be without their best offensive player, Miles Sanders. Deep threat DeSean Jackson also is out. So is Dallas Goedert, who has been their best tight end. Need I mention the Eagles long ago lost all of their best offensive linemen. I definitely see Washington's defensive line winning the battle of the trenches. 
On the Washington skill position side, Alex Smith, Antonio Gibson and Terry McLaurin are all questionable. That's Washington's best QB, RB and WR. All three would be limited if they were to play, especially McLaurin and Smith.
The depleted Eagles secondary is vulnerable. Smith always has been a game-manager, though. If Smith can't play because of a calf injury than Taylor Heinicke would be under center for Washington. Heinicke makes Smith look like Brett Favre.  
Philadelphia has one of the better defensive coordinators in Jim Schwartz. The Eagles will be up for this home contest, which is the nationally televised Sunday Night Game. This is their Super Bowl for what has been a hugely disappointing season.
Lots of running and short, safe passes should keep the clock moving in what I anticipate to be a highly-intense defensive battle played in the rain.