Thomas Tuchel makes five changes to the side that drew at Leeds on Saturday. The flat back four has been dispensed with in favour of his standard 3-4-3 formation, and back comes Kurt Zouma in place of Andreas Christensen.
On the flanks, Ben Chilwell is rotated out for Marcos Alonso while Reece James takes over from Christian Pulisic.
Jorginho and Mason Mount are suspended so in come Mateo Kovacic and Timo Werner. The matchwinner in Bucharest, Olivier Giroud, is only on the bench.
But, Diego Simeone goes with Luis Suarez and Joao Felix at the top of a 4-4-2 formation, which sees two changes from the side that played out a goalless draw at Getafe at the weekend. Brazilian Renan Lodi is it at left-back in place of Mario Hermoso while Belgian winger Yannick Carrasco is back to play on the wing instead of Angel Correa.
Right-back Kieran Trippier makes a return to England while Koke captains the team.
Chelsea head coach Thomas Tuchel has warned his players about dwelling on their win in Bucharest when their focus should purely be on tonight’s match.
Despite their one-goal lead, there are certainly reasons for Chelsea caution. Very much in the mould of their manager, Atletico Madrid are a club that never know when they’re beaten.
In their European Cup and Champions League history, Atleti have a 50% progression rate when losing the first leg of knockout games, progressing from four of eight previous ties in these circumstances.
Tuchel has therefore sounded a note of caution to his players.
The Chelsea boss said: “If we start thinking too much about the [first leg] result, we stop thinking about the process. We have to be in this game on the level against a team like this. I hope we are not influenced by the first result. We want to play a high-intensity game to put them to their limits. It is clear that you need two top-level games to go through.”