Poor Mertesacker fell over the other day because standing up is really difficult. Combine that with running and trying to look at a football and you've got an injury waiting to happen!
For those of you unfamiliar with this kind of injury, that's what happens when you hurt your ligaments in your ankle. It's very, very sore, and always really awkward when it happens to you or one of your friends, because it only happens when you are trying to do something really normal like pass a ball, or as Jack found out recently, header one. As your compatriot lies on the ground desperately trying not to cry and thus show weakness, you remain unsure as to whether you should (a) go over and ask them if they are OK, despite them clearly not being (b) remain silent and wander about the rest of the pitch or (c) laugh, because it was really funny and they are a retard for not being able to walk upright like a human.
In Mertesacker's case it is definitely c. Every time. Mesmerising.