What we know is that Chelsea are going through a difficult period where their game was not very convincing throughout several matches but in fact it was successful when they faced Dortmund but unfortunately they met Real Madrid in the quarter-finals which would be a tougher challenge for Chelsea not only in terms of players but coaches even Graham Potter must be able to use good game strategy and tactics because that's one that can be relied on when you want to win, but in my feelings it is in the end that Real Madrid will qualify.
Why so? Because Chelsea are still inconsistent, especially when they have to face a team that has won a lot, mentally it will fall, but again from my perception, maybe no one knows the result or there will be another surprise in the quarter-finals which will begin.
Your uncertainty about the game's outcome demonstrates how much you believe Chelsea can still beat Real Madrid despite their inconsistency in matches. We've seen surprises in the Champions League before, and this time may not be any different. Chelsea has a fairly good record against Real Madrid in recent Champions League meetings, but Real Madrid is also wary of what the outcome of the game might look like. The Chelsea underdog could still win, but it all depends on how Real Madrid performs in the game.