David Moyes is looking to for the upset.
West Ham manager David Moyes will look to get the better of his former team when the Hammers go to Manchester United in the FA Cup fifth round tonight.
The Scot was sacked just 10 months after replacing Alex Ferguson as United boss.
Kick off at Old Trafford is 7.30 and United will be without the injured Paul Pogba.
Before that at 5.30, Burnley welcome Bournemouth to Turf Moor.