The Red Devils will need to see off the Hammers at Upton Park to book their place at Wembley, with Crystal Palace taking on Watford in the other tie of the last four.
Manchester United or West Ham will face Everton in the FA Cup semifinals, with Crystal Palace taking on Watford.
The Red Devils rescued a 1-1 draw against the Hammers at Old Trafford on Sunday and will look to claim their place in the last four in the replay at Upton Park.
If they can get past Slaven Bilic's team, which has not lost since August at home in any competition, they will face Everton, which beat Chelsea in the quarterfinals.