Chelsea v AC Milan
Graham Potter will take charge of his third match as Chelsea manager, his second-ever in the Champions League, when the Blues play AC Milan.
Chelsea are bottom of Group E with just one point while their opponents are top and have yet to lose a game in Europe this season.
As the halfway point of the group stages nears, Chelsea need to start getting more points on the board if they are to qualify for the round of 16.
"We are playing against a different team, a different way of playing. A top team, just like Salzburg, every game is different," Potter told reporters.
"We have to be really, really good to get the result we want. We try for three points, it's important to win your home games but we are playing against a top opponent. We have to create a top atmosphere for our fans."
Potter's biggest selection dilemma is in goal, with the Englishman quick to praise Edouard Mendy and Kepa Arizzabalaga who are both fit to play.
There were no hints dropped about who will be the long term number one, although the manager is keen to give Kepa his chance.
"Firstly, I want to help Kepa enjoy his football and play at a really good level, which I think he did against Crystal Palace (a 2-1 win for Chelsea) and I want to help Eddy get fit and ready to play.
"Then we've got two goalkeepers and in an ideal world you want football to decide."
They will most likely be up against returning Blues striker Olivier Giroud who has scored six times in 11 appearences for the Rossoneri.
In the other Group E fixture, Salzburg take on Dinamo Zagreb.
Manchester City v FC Copenhagen
Manchester City welcome FC Copenhagen in Group G and looking to maintain their 100% record in this season's competition.
City have won their opening two games, beating Sevilla 4-0 and coming from behind to overcome Borussia Dortmund 2-1.
Pep Guardiola's side will be without Kyle Walker, but Rodri is expected to return from injury after missing the Manchester derby.
Despite starting as clear favourites, Guardiola warned their European opponents will be "really good".
"We know how important our games at home are and tomorrow will be no exception. When I face this kind of team from Northern Europe, they are always really good.
"We have to be careful. If we can win three games, we will be so close to going through to the next stage," he added.
Copenhagen have picked up one point so far in Europe, against Sevilla, who face Dortmund in the second Group G match.
