Indeed, Chelsea performed well in the UCL. They have a chance to win like Tuchel. But with the current conditions I doubt it. I don't think current players can compete with Man City, Munich or other big clubs. In 1/16 they will play Dortmund. I don't underestimate Chelsea, but Dortmund can always surprise. Chelsea must be vigilant. Even though that game is still a long way off, there is a chance Chelsea make a big transfer maybe that could change the chances of getting to the Final.
I don't think that any transfer can seriously change the chances of the teams (unless of course it's Haaland + Mbappe, but they hardly want Chelsea plus they can no longer play for another club in the Champions League this season). Maybe we will see Ronaldo's move that has been talked about so much? He's not showing anything special this season, but he has a certain Champions League magic associated with him.
Don't undermine the power of transfer. It bring new challenges, new spirits, new strengths and new expectations. It must not be Haaland type of transfers but any good player with the determination to make some difference will do many wonders.
Chelsea has been having many injury problems after some of their good defenders left the club like Rudiger. Chelsea need good players from January window.