Mourinho’s troops will welcome the in-form Gunners to Old Trafford tomorrow night.
The north Londoners go into the match riding a 19-game unbeaten run, which they maintained this past weekend with a 4-2 win over Tottenham.
In stark contrast to Arsenal, United have won only one of their last four league games and have shipped six goals in that time.
Mourinho could be without the services of eight first-team defenders for tomorrow’s game, which he’s expecting to be a ‘difficult’ one.
“We will have a very difficult match,” the Portuguese said in his pre-match press conference. “They are a good team who have had a good run of results.”
Although Mourinho admits his side face a tough task to beat Emery’s men, he’s insisted the visitors are fully aware of the magnitude of the task that awaits them.
He added: “But in spite of our selection issues, they know it won’t be easy either.”
Tomorrow’s match will be Mourinho’s first game against the Arsenal since Arsene Wenger left the club in May.
And he admits preparing for Emery’s side is a completely different proposition to preparing for the Gunners when they were managed by Wenger.
“Yes, it’s different [team],” Mourinho said. “I have my opinion but keep [it] for myself, different yes, and a very difficult match for us because we are going to play against a good team in a good moment.
“[Also] without accumulation of matches because they are playing Europa League and when you play Europa League you normally play with second choices and give good rest to the players.
“We have to play to the max, with accumulation of matches, and then you arrive in this moment in December and many teams pay the price of that.
“That is not the motivation you want as a team as a club but to develop players fresher is a good way to do it.”
On United’s injury crisis, Mourinho said: “We are going to be in difficulties again to build the team.
“We are again going to have to make adaptations and compensations to try to give some balance to the team.
“But then I believe we are again going to have the spirit to fight and to try and to win the match.”
