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.
Chelsea already done good job in last summer window but sadly due to change of coach things not going into their way, so now they are struggling in Premier League badly and have average performance into Champions League with Graham Potter is surely now looking for some improvement which needs few players which can work with in his strategy hopefully now in this coming winter transfer window they will be able to have few players which help them for increasing their performance and quality for the better results which is not easy because we have few teams those are doing amazing job and now allowing opponents to have positive results, but this window is surely vital for many clubs for both type results like negative or positive no one can predict, but surely things could be entertaining for the soccer community.