It's also a massive game for Louis van Gaal who is under pressure at United after failing to deliver Champions League football for next season.
Injuries easing for the Reds
At his pre-match press conference, van Gaal revealed some good news on the injury front as he says he now has 27 players to choose from for the game this weekend.
Matteo Darmian and Marcos Rojo are fit and ready to play this weekend which gives van Gaal more of a choice in the fullback areas. Marouane Fellaini is also available again after finishing his three-match suspension and is likely to be in the squad for the game.
Luke Shaw and Bastian Schweinsteiger will both once again miss the game but the good news is Shaw is now back in full training as he looks to step up his work before being fully fit for pre-season. Schweinsteiger is also not that far away from a return to full fitness after being named in the Germany Euro 2016 squad this week.
So with all this being said, who is van Gaal likely to select in order to win the FA Cup and finally bring some success to the club after three years without a trophy?
Rojo set to be only change in the back five
David de Gea will once again start in goal after having such a superb season. Antonio Valencia is likely to start once again at right-back after playing well since his return from injury. Chris Smalling and Daley Blind are likely to start as the two centre-backs after forming a formidable partnership this season.
Fellaini to come back into the side to help with set pieces
Rojo is set to come into the team at the expense of Cameron Borthwick-Jackson who is likely to be dropped for the more experienced player. Michael Carrick is likely to play in midfield in what could be his last game for the club with the returning Marouane Fellaini likely to be his partner due to how many goals Palace have scored from set pieces this season.
Wayne Rooney is likely to play further forward in midfield after playing well there in the last few games. Anthony Martial will start from the left wing due how well he has done there all season with Jesse Lingard likely to play on the right due to his work rate.
Marcus Rashford will once again start as the lone striker after scoring in his last game against Bournemouth and also due to how well he stretches the opposition defences which will be crucial on a big Wembley pitch.
Predicted XI: De Gea; Valencia, Smalling, Blind, Rojo; Carrick Fellaini, Rooney; Martial, Rashford, Lingard.