Translation please!

I know I'm not a big football fan and therefore may not be thoroughly conversant with the terminology, but could somebody please explain what the referee (Claus Bo Larsen) at the Liverpool-Chelsea match the other night meant when he said:

However, Larsen said: "When a player tried to jump after a goalkeeper who has the ball, to prevent the enemy from turning, then he must also pay at a bank. So he received the card anyway."

What enemy, turning where or from where or into what? Pay what at which bank?

Must be a language thing.