Manchester City have opened up a huge advantage in the Premier League title race - and Chelsea have it all to do to even get close to them.
But if Thomas Tuchel's side can win at Etihad Stadium on Saturday, they will make a dent in Manchester City's 10-point lead at the top.
To get you in the mood, we've put together this list of players who have featured for both sides. You've got six minutes to name all 12.
Use #bbcfootball to share your results - good luck!