Our meeting with David Moyes's Hammers, who are currently fourth in the league having already topped their points total from last campaign, will take place on Sunday 14 March, with a kick-off time of 19:15 GMT.
The game will be shown live on Sky Sports in the United Kingdom.
The visit of the in-form Irons, winners in seven of their nine Premier League fixtures since the turn of the year, follows hot on the heels of three tricky-looking away fixtures for Ole Gunnar Solskjaer's Reds.
We play Chelsea in London on Sunday 28 February and return to the capital three days later to take on Roy Hodgson's Crystal Palace.