#2 injuries
The sight every club fan dreads is seeing their star player clutching their ankle in agony or feeling their thigh after an awkward turn forcing them off the pitch.
Every fan fears important members of their squad picking up an injury, but particularly when it is picked up in an 'unimportant' or 'unnecessary' friendly game whilst on international duty is it especially frowned upon by club fans.
Because friendlies are non-competitive and often at times pointless, fans dread any of their star players potentially picking up an injury or be unnecessarily fatigued by the demands put on their players by national sides.
Jack Wilshere was one player to pick up an injury whilst on international duty with England. The Arsenal midfielder picked up a knee injury which sidelined him for England's games with the Netherlands and Italy.