Perhaps it was the imminent prospect of throwing away a lead and failing to win for the ninth time this season, perhaps it was the sense of a season still on the slide or perhaps it was the news that interim coach Ralf Rangnick has banned them from eating bacon butties, but there were around five minutes left of their 1-1 draw with Southampton when Manchester United's players started to lose their heads.
Paul Pogba, who had sparkled only intermittently, was penalised for an innocuous foul on Southampton's outstanding teenage forward, Armando Broja, and suddenly all the pent-up frustration in a group of United players who seem full of resentments and entitlement, burst into the open in a collective fit of petulance.