Given that Chelsea just bought themselves new left back, do you think that he is going to be better at rivaling Cesar Azpilicueta, than Filipe Luis?
No. Azpi is their best fullback and has been playing at a very high level, even on the left. Rahman was brought in to allow Azpi to move to his natural right, replacing the horrendous Bane.
This could be an option, but I doubt that Chelsea would sell Filipe Luis, if that was the case. As for the quality if think that Baba Rahman is not as good as Azpilicueta, and is not going to be able to replace him.
Luis Filipe has returned to Atletico Madrid. I believe we are more likely to see Rahman as left back and AZP as right back, as Ivanovic has been rather awful lately. That is of course, if Rahman plays well enough.