It's common knowledge that it's unwise to take on Zlatan Ibrahimovic.
The 6ft 5in Sweden international is an intimidating opponent - for his impressive frame as much as for his skill with a football. The striker, now at AC Milan, enjoyed just short of two successful seasons at Manchester United, during which time he scored 17 goals in 33 league games and proved he can 'do it' in just about any league in the world.
No doubt Ibra's United teammates were glad he was lining up for them and not against them. But you don't achieve what Ibrahimovic has in world football without being demanding, both of yourself and those around you. And after his on-pitch demands got too much for Marcos Rojo, the two had to be separated by their boss in the dressing room at half-time.