I don't understand why the Bayern Munich management sacked Nagelsman. Nagelsman was a good enough coach. And Bayern Munich's performance was not weak. Even so, the Munich management decided to fire Nagelsman. Potter, on the other hand, has had plenty of time to stabilize his team. But he failed completely. Chelsea management should have taken the decision to sack Potter earlier. However, Nagelsman looks more likely to be Chelsea's coach. Because Chelsea can't find an experienced coach like Nagelsman at the moment. If Nagelsman becomes the coach of Chelsea, I believe he can stabilize the team.
You cannot eat your cake and have it, Potter don't have enough time to make a come back, they were having hard time in Premier League, they had hard time in FA cup, the only place they had hope is Champions League here and they will be challenging Real Madrid, an opponent team that they couldn't beat the last time they met, if I am the owner of Chelsea, he deserved to live the club with immidiate effect. Nagelsman is yet to make any official statement regarding his sack, may be it is similar to what happen to Tuchel when he was in Chelsea.
Given Chelsea's disappointing performances in every Premier League match, the chances of them doing well in the Champions League are slim. If not for their opponents in the Champions League, Real Madrid, Chelsea would have had a chance to qualify for the semi-finals. However, Madrid is a very experienced opponent. And Madrid's chances of winning the La Liga title are slim. So they will try their best to win the Champions League title. This is why it is impossible for Chelsea to perform well against Madrid without an experienced coach. My guess is that Chelsea will lose both matches against Madrid.