Manchester United manager Louis van Gaal has warned that he expects a strong reaction from Arsenal as the Gunners look to bounce back from their Champions League defeat.
United travel to the Emirates on Sunday -- and Van Gaal has warned the Premier League leaders that Arsene Wenger's men are capable of a significant response to their 3-2 home loss to Olympiakos on Tuesday.
He told MUTV: "I think Arsenal can come back off a defeat. They have shown that a lot of times.
"I think Arsenal are one of the best teams in the league, in a technical and tactical sense -- maybe the best. I like the way they play.
"Nevertheless they haven't won so much, so you have to look for that improvement with their team."
Van Gaal has expressed concerns that his own side, who beat Wolfsburg 2-1 in the Champions League on Wednesday, could be affected by fatigue.
He said: "It is very difficult. Arsenal had one day more because they played the day before us, so it shall be a difficult game."
The Dutchman has also stressed the need for United to keep improving, despite the Wolfsburg win being their fourth in a row in all competitions.
He added: "We can improve and we have to show it against Arsenal -- it is not an easy match but we have to show it."
Earlier this week, Red Devils midfielder Morgan Schneiderlin suggested the team were starting to silence the doubters.
But defender Phil Jones feels there will always be critical voices, and said: "It [being top] is a great boost for us and it raises a few eyebrows.
"Hopefully we can keep raising a few more, because our results and performances have been very good this season and hopefully we can keep it going.
"When we were winning games, it was never enough goals -- it was 4-0, we should have won 10-0.
"You always get that. They are there to make judgmental comments."