Jose Mourinho is facing the worst defensive crisis of his Manchester United tenure as Arsenal prepare to visit Old Trafford.
The squad arrived at Manchester's Hilton Hotel on Tuesday evening ahead of the game, with concerns over a number of players.
Full-back Ashley Young and Luke Shaw are out, the former is suspended while the latter was forced off during Saturday's 2-2 draw with Southampton.
Chris Smalling and Eric Bailly travelled with the squad but, earlier on Tuesday, Mourinho ruled the pair out of the game. Antonio Valencia is also expected to miss out, with Victor Lindelof a definite absentee.
Darmian, who campaigned for a summer exit which never materialised, should play but there are also question marks over Phil Jones's fitness. Forgotten man Marcos Rojo is in the squad.
Diogo Dalot could come in for his first Premier League start and Nemanja Matic may be moved back into central defence as emergency cover. Scott McTominay has also travelled.
In attack, Romelu Lukaku and Marcus Rashford should be fit after also struggling against Southampton. Alexis Sanchez is out for a number of weeks.
Additional reporting by Press Association.
