The Red Devils suffered a surprise 1-0 loss to 20th-placed West Bromwich Albion at Old Trafford last weekend.
Jay Rodriguez netted a 73rd-minute winner to hand Manchester City the Premier League title with five games to spare.
Manchester United are 16 points behind the newly crowned Premier League champions to highlight the gap between the derby rivals.
The Red Devils lost 2-0 to Tottenham in the Premier League at Wembley back in February following a resounding loss.
Manchester United are looking to win the competition for the first time since 2015 when Louis van Gaal was still in charge.
Former Chelsea FC striker Sutton believes the Red Devils will find it very difficult to beat Tottenham in the FA Cup.
“Can Man United win the FA Cup?” Sutton told BBC Radio 5 Live. “It’s going to be a hard ask. If they don’t, it will be same old questions.”
Manchester United are in second place in the Premier League table and a point ahead of Liverpool FC in the race to finish as runners up.
The Red Devils signed Chile international Alexis Sanchez in a swap deal from Arsenal in the January transfer window.
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