United welcome in-form West Ham to Old Trafford for the second time this season with a place at Wembley at stake for the winners of this FA Cup quarter final.
The league fixture between these two ended goalless in December, but Slaven Bilic's Dimitri Payet-inspired side have beaten Arsenal, Liverpool and Manchester City on their travels this term and arrive at Old Trafford on a six-match unbeaten run.
In their final campaign at Upton Park, the Hammers are enjoying a splendid season and their 3-2 win at Goodison Park last weekend- from 2-0 down- lifted them above United and to within two points of the Champions League positions.
West Ham have knocked out Championship sides Wolves (1-0) and Blackburn (5-1) and sent Liverpool packing after a replay in round four to get this far.
The Reds were knocked out by eventual winners Arsenal at this stage last year and it's been well documented that we've not won the FA Cup since 2004 and victory in this one would set up a first semi-final since 2011.
Louis van Gaal's side will be without Wayne Rooney, Luke Shaw, Ashley Young and the suspended Juan Mata but Bastian Schweinsteiger, Marouane Fellaini and Antonio Valencia are all available again and could feature as United's injury crisis eases.
Phil Jones and Cameron Borthwick-Jackson are nearing returns and Jesse Lingard looks set to come back into the squad after missing Thursday's European defeat at Anfield.
"We are still in three competitions, so we need to fight- we still have the chance to win a trophy and you have to believe in that" said Van Gaal.
"There is of course much more pressure on us now, but it is also possible that we win against West Ham and then we can play at Wembley which will be the first time for me" added the boss.
"We have to go for everything and that's what we want- we'll try our best to win a trophy and make it a good season".
Crystal Palace and Everton sealed their quarter final spots with wins over the weekend whilst Arsenal host Watford in the other last eight tie.
Form guide: United W W W W L L West Ham W D W W W W
Match odds: United 21/10 Draw 13/5 West Ham 16/5 (United to win FA Cup: 6/1)
Referee: Martin Atkinson