Soccer mainly involves kicking, so it stands to reason that sometimes soccer players kick each other, both by accident and on purpose. Sometimes, they even kick each other in the face.
Ths, though, is just gratuitous.
This tackle occurred in the Argentinian second division, and it is one of if not the worst tackle we have ever seen. This is the sort of thing you normally only see when FIFA starts glitching. Here's a look at the aftermath:
That looks really bad, but watching the tackle again it looks like it coule, and perhaps should, have been worse.