Thomas Tuchel's side must finish the job against Porto at Stamford Bridge having beaten them 2-0 in the first leg.
The Champions League semi-final stage is so close now but the Blues must remain switched on to avoid calamity.
They head into the game off the back of Saturday's 4-1 win over Crystal Palace and should be full of confidence that they can reach the last four against either Real Madrid or Liverpool.
Follow Sportsmail's Will Griffee for live Champions League coverage of Chelsea vs Porto, including scoreline, lineups and build-up.