There have been some great players who have represented both Chelsea and our next opponents Southampton. Find out if you remember them all in this quiz...
The list of people who have played for both clubs includes some of the best strikers ever to wear a Blues shirt, a host of internationals from England and around the world, plus several Chelsea Player of the Year winners. With the Saints our next opponents, at Stamford Bridge in the Premier League on Saturday afternoon, it's the perfect time look back at their time with both clubs.
But how well do you remember them and their careers at Stamford Bridge and St Mary's, or The Dell for some of the older names? Find out and whet your appetite for the match with this quiz. Good luck!
If you fancy using that Chelsea knowledge to try to win some fantastic prizes while competing against your fellow Blues fans, don't forget to enter the Play Predictor for Saturday's match.