The Reds Devils have started the season poorly and they cannot afford to keep dropping points if they want Champions League football next year.
Meanwhile, Arsenal are heading into this game full of confidence on the back of a North London derby win.
Unai Emery has got his side firing all cylinders and the Gunners will be looking to pile further misery on Mourinho here.
The home side are plagued with injuries right now. Sanchez and Lindelof are ruled out. Ashley Young is suspended and the likes of Eric Bailly and Marcos Rojo are doubts as well.
Mourinho is expected to make four changes to the side that drew against Southampton. McTominay, Pogba, Rashford and Young could make way.
Arsenal will be without Monreal, Welbeck and Koscielny due to injuries. Xhaka is suspended.
Predicted Manchester United Starting Lineup (4-3-3): De Gea; Dalot, Smalling, Jones, Darmian; Fellaini, Matic, Herrera; Martial, Lukaku, Lingard
Predicted Arsenal Starting Lineup (4-2-3-1): Leno; Bellerin, Mustafi, Holding, Kolasinac; Torreira, Guendouzi; Mkhitaryan, Ramsey, Aubameyang; Lacazette