Midfielder AndriyArshavin aggravated a groin injury playing for Russia in a World Cup qualifier against Wales in September and full-back Kieran Gibbs picked up a minor ankle injury with the England Under-21s.
Spain midfielder Cesc Fabregas capped a fine performance with two superb second-half goals before substitute Eduardo made it 6-0 from close range with two minutes to go after Andriy Arshavin's shot hit a post.
Arsenal had earlier taken a first-half lead in the match courtesy of an AndriyArshavin goal, only to see United hit back to take the lead through a Wayne Rooney penalty and an own goal from Abou Diaby.