Chelsea performance may improve before the match but still I am not seeing Chelsea qualifying to next around and knock out Real Madrid this season, all this is due to Chelsea weak finishers, infact Chelsea is not that bad in term of ball possession but seriously lacks finishing players, so they do play in term of ball possession but always lack of scorers.Therefore, I can confidently predict that Real Madrid will defeat Chelsea because I am unable to predict who will get past Real Madrid's formidable defense and go on to score goals for Chelsea.
They must improve their defense to protect their goal first because Real Madrid have good attacking system with many attacking players who can score goals against Chelsea. If Chelsea can prevent Real Madrid to have goal, a longer a match goes they will have better chance to exploit defense of Real Madrid. In big matches like this, one goal can decide a winner who don't need to dominate match to win after all.
However, I really don't think Potter will be able to help Chelsea achieve this. In addition Chelsea will not have Thiago Silva for at least one of two matches with Real Madrid.