United will come into the game full of confidence, having secured a valuable 2-0 Europa League quarter final first leg win in Granada on Thursday night. Ole Gunnar Solskjaer's men are also unbeaten in ten Premier League games.
Tottenham returned from the international break with a woeful 2-2 draw at Newcastle last time out, with Arsenal-loanee Joe Willock equalising for the Magpies in the 85th minute. Mourinho's side have just one win in their last three league matches, coming in a 2-0 victory over Aston Villa - just a few days after embarrassingly exiting the Europa League at the hands of Dinamo Zagreb.
A win on Sunday would be crucial to closing the gap on the top four, so here's who should start the game for Spurs.
1. Goalkeeper & Defenders
Hugo Loris (GK) - No doubt a quality goalkeeper and, at times this season, has single-handedly saved his side from any further embarrassing results.
Serge Aurier (RB) - With Matt Doherty still out, Aurier will likely come in to replace Japhet Tanganga at right back.
Joe Rodon (CB) - Proved his quality last time out. Has very much earned his spot for Sunday's huge clash.
Toby Alderweireld (CB) - Missed the previous match but should come back into the side to provide some experience.
Sergio Reguilon (LB) - Can be a real threat going forward, but will likely have a tough day at the office defending against Daniel James and attacking against Aaron Wan-Bissaka.
Pierre-Emile Hojbjerg (CM) - The leading tackle-maker in the Premier League this season (82) should provide composure and a level head in the Spurs midfield.
Tanguy Ndombele (CM) - Can be a real creative force on his day.
Erik Lamela (AM) - Was welcomed back from suspension for a cameo against Newcastle but could start this one to add a bit of spice and flair to the Spurs midfield.
Lucas Moura (RW) - May be pushed out wide for this one and, while he's been a stand out for Spurs of late, could be in for a rough time against Luke Shaw.
Harry Kane (ST) - His future may be uncertain, but how can he not start? Another two strikes last time out puts the England captain up to 24 goals and 15 assists in all competitions for the season - ridiculous.
Son Heung-min (LW) - Fit enough to feature off of the bench against Newcastle but will be brought into the first XI as soon as possible to add to his 27 goal contributions this campaign.