As the Arsenal players trudged off the Emirates pitch on Tuesday night, the few fans that remained in the stadium gave their team a half-hearted applause.
Of the many that chose to leave the stadium, many also inundated sports radio shows to complain about Arsenal manager Arsene Wenger's decision to rest Petr Cech during their team's 3-2 loss to the Greek side Olympiakos. A disastrous result for the Gunner's Champions League hopes.
Arsenal fans were annoyed that Wenger had changed his team and appeared not to consider just how important Champions League success for the North Londoners would be.
There will be no need to introduce Wenger to the importance of Sunday's match against Manchester United. If Wenger is focusing his attentions this season challenging for the Premier League title, then Sunday's match will be his chance to restore the fans belief in him and get the better of a bitter rival and a fellow championship contender.
Arsenal vs Manchester United also needs no introduction. The two teams have fought out a bitter rivalry for decades, going back to the 1930s until day.
For Wenger several key questions hang over his team selection. Surely Petr Cech will return in the Gunners goal and replace David Ospina? And with Laurent Koscielny picking up a hamstring injury during the midweek loss and Olivier Giroud ready to come back into the side and challenge Theo Walcott for a place in the Arsenal attack, fans will be waiting with baited breath to see the team sheets as they are announced on Sunday afternoon.
For Manchester United boss Louis Van Gaal preparations coming into his visit to the Emirates have been far simpler than his counterparts.
Sitting pretty at the top of the league, United has at times been awkward, disjointed and confused, yet managed to find victory after victory and build momentum.
Momentum that will have also been boosted by the victory midweek against Wolfsburg, where the Red Devils showed great character in overcoming a 1-0 deficit to come back and win 2-1.
Key midfielder Michael Carrick will be available for selection again and could come into the United midfield ahead of Bastian Schweinsteiger.
Van Gall may well be relishing the opportunity to release new signing Anthony Martial, with his electric pace up against an Arsenal back four who without Koscielny will be lacking the speed they may need.
After Sunday's match key questions will be answered about which of these two sides are better prepared for a title challenge.
The win could be a vital boost for Arsenal, having been defeated by Chelsea two weeks ago the win will reaffirm their title credentials, but United will feel that they are on-form favorites to leave North London with the three points.
As the radio phone lines start ringing again on Sunday night, Wenger will be hoping that his team have proven him right and claimed the scalp of their rivals and that he and the Arsenal fans can forget about Tuesday night.
When: Sunday 4th October
Where: Emirates Stadium, London
Kick-Off: 11:00 AM ET
TV Links: NBCSN
Live Stream: NBC Sports Live Extra, Telemundo