Louis van Gaal is expecting Arsenal to be much improved against Manchester United

Louis Van Gaal is wary of a backlash from Arsenal when Manchester United visit the Emirates Stadium on Sunday.

While United were victorious this week in the Champions League against Wolfsburg, the Gunners suffered a surprising defeat on Tuesday when they lost 3-2 at home to Olympiakos.

With back-to-back games against Bundesliga champions Bayern Munich looming, Arsenal have it all to do to qualify from Group F.

Despite Arsenal's struggles, Van Gaal is expecting a stern test of United's title credentials from Arsene Wenger's side on Sunday.

"We are happy but I think Arsenal can come back from a defeat," Van Gaal said. "They have shown that a lot of times.

"Arsenal are technically and tactically the best team in the league. Nevertheless, they haven't won so much, so you have to look for that improvement with that team."

One worry for Van Gaal heading into the game is the tight turnaround from Wednesday's clash with Wolfsburg.

Michael Carrick is fit to face Arsenal on Sunday

The United manager confirmed he will have midfielder Michael Carrick available for selection but he has not yet decided to what extent he will rotate his squad.

"The solution is recovery, recovery, recovery," Van Gaal stressed. "That is why it's so difficult to prepare for the match against Arsenal.

"As a manager you want to prepare on the pitch and you cannot do it because players need to be fresh.

"The other solution is to change your squad so we have to see how the evaluation is from my fatigue specialist."

Louis van Gaal celebrates victory victory over Wolfsburg with Chris Smalling

Chris Smalling was the hero for United on Wednesday when he guided home Juan Mata's sublime flick to give the home side all three points.

The England international has developed into one of the club's most important players under Van Gaal but the Dutch boss insists the only person who deserves credit for that is the player himself.

"When he does things, he does it always by himself," Van Gaal said. "I help him with advice, demands and training sessions, and by showing images to improve him.

"But he has to be open and he has to perform on the pitch. He does everything himself. The greatest compliment you have to make is to Chris and not to me."