Chelsea’s current standings in the group mean they will be out of the competition at the group stage if they don’t get maximum points against AC Milan.
If Chelsea draw or lose to AC Milan tomorrow and next week, their elimination from the Champions League this season may be confirmed depending on the results in the other Group E fixture between Salzburg and Zagreb.
The 2021 Champions League winners will likely do their best to avoid elimination or dropping into the Europa League and if that must be avoided, it must begin with a win against AC Milan tomorrow.