We continue to count down to Christmas with our own take on a traditional advent calendar, as we bring you a new player-based quiz to enjoy every day. Today's focus is on a German who had a big impact in four trophy-laden years.
On every date between now and Christmas, we will bring you a quick quiz on a famous player or players who have worn that number on the back of their shirts for Chelsea. Michael Ballack wore the number 13 shirt throughout his time in south-west London, but how much do you remember about the midfielder's glittering career?
Just like with an advent calendar, you can come back and open a new quiz every day until Christmas Day. Unfortunately we can’t give you all a chocolate to enjoy with your quiz, but feel free to treat yourself if you score high. Good luck and merry quiz-mas!