Jose Mourinho used three at the back for the second half against Valerenga last weekend and, while the Norwegian side were indeed awful, Manchester United ran riot.
Another notable aspect – something that could realistically replicate itself next season – was the damage inflicted by the striking duo of Romelu Lukaku and Anthony Martial.
The bustling, energetic presence of both Lukaku and Martial was enough to unsettle Valerenga’s back four in Oslo. When the pair darted forward there was little the home side could do to track both of them, leaving McTominay and Andreas Pereira with plenty of space to exploit.
Using Marcus Rashford alongside the Belgian, therefore, could be a golden recipe. Not many back fours are used to going up against two up front these days, with the practice largely abandoned in Europe’s top five leagues, but deploying Henrikh Mkhitaryan behind the two could wreak absolute havoc and help to cement an efficient plan B ahead of next season.