It is too difficult to talk about Chelsea's title chance in the Champions League in the near future now. Because they have bigger concerns to deal with first. It is very hard to predict what will happen after Tuchel's departure and Potter's arrival. They will need a lot of time to see the results of new changes in the team. People have many question marks in their minds because of Potter's being very inexperienced about big teams and big tournaments like this one. I won't be surprised if they even continue in the Europa League this season. It won't be easy for them to collect enough points against Milan to increase their chance for next round.
Maybe we are still at the beginning of the season now and I'm prejudiced about their future. But as long as they don't solve their scoring issues this season won't be bright for them neither in the Champions League nor in the English Premier League.
Chelsea are currently at the bottom of Group E, and only has 1 point from 2 matches indeed very small chance to qualify from the group stage.
Especially as you said Chelsea chose Graham Potter as the new coach, who has no experience dealing with big teams and also inexperienced
in the Champions League. This fact makes some people become pessimistic about Chelsea. AC Milan is Chelsea's strongest competitor in Group E,
so like Chelsea it will be difficult to face AC Milan. Even Chelsea against Dinamo Zagreb and Salzburg were unable to win, so Chelsea needed a miracle
to qualify from the group stage. Another problem from Chelsea, they are also not productive in scoring goals, Aubameyang, who is expected to be
a goal machine, has not shown satisfactory performance. Too many problems have happened to Chelsea, this season will indeed be quite a difficult season
for Chelsea.