TEAM NEWS:
Manchester United: Mourinho's side are short of defensive options. They hope Chris Smalling and Eric Bailly recover from respective foot and back problems.
Ashley Young will miss the game through a one-game suspension, with Dalot expected to replace the England international.
Phil Jones is reportedly nursing an injury, and both Luke Shaw and Romelu Lukaku are doubts following injuries, however expected to play.
Alexis Sanchez will not face his former club after Mourinho confirmed the Chilean is unlikely to play again this year, with the injury that he suffered in training last Thursday.
Arsenal: Granit Xhaka will also miss the game through suspension having after accumulating five yellow cards.
Playmaker Mesut Ozil is unlikely to feature because of back spasms.
WHO IS SAYING WHAT?
Manchester United boss Jose Mourinho:
"We will have a very difficult match. They are a good team who have had a good run of results. But in spite of our selection issues, they know it won't be easy either.
"We don't need a miracle [to finish in the top four] at all. I think we need a good run of results and we don't need to waste points where we shouldn't be wasting them."
Arsenal boss Unai Emery:
"It will be a very big challenge for us and it will confirm our good moment, or whether we need more.
"It is very difficult to win there because they are a very big team with big players and have a big atmosphere pushing them, but it is an exciting match and my motivation is very big."
Form:
Did you know?
The 82 most recent league and cup encounters had featured one or both of Sir Alex Ferguson and Arsene Wenger, first time since 1986 that neither of them will be involved.
Manchester United are unbeaten in 11 home league matches against Arsenal since September 2006 (W8, D3).
The Gunners are unbeaten in their last 12 league games (W9, D3), and 19 matches in all competitions (W15, D4).
Possible lineups:
Manchester United: De Gea; Dalot, Smalling, Jones, Shaw; Matic, Herrera; Lingard, Pogba, Martial; Lukaku
Arsenal: Leno; Sokratis, Mustafi, Holding; Bellerin, Torreira, Guendouzi, Kolasinac; Ramsey, Aubameyang, Lacazette