After most transfers seem to have been finalized, we can safely consider Chelsea to have 5 first team players in their defense. Chelsea’s usual formation is going to contain 4 defenders, unless they switch to a 3-man defense during pressure situations when a lot of attackers are required.
Chelsea skipper John Terry had a strong season last year. He is expected to be a key player but his age and slowness is against his cause. This season, Branislav Ivanovic, who can play both central as well as right back is expected to share the spot with the ageing captain. English International Gary Cahill will be an important and regular player in central defense as he is of the correct age and has developed well last season. Youngster Kurt Zouma is expected to fight for his place and play as a regular substitute in his first season. Zouma is has a strong role to play in cup matches and has a chance to impress the manager as well.
Branislav Ivanovic, Filipe Luis and Cesar Azpilicueta are the three main fullbacks in the squad. Azpilicueta can be employed in both the positions while Ivanovic can be played at Right Back as well as Centre Back. Filipe is likely to be the first choice Left-Back with Azpilicueta as the substitute. The versatility of the Spaniard and the Serb, allows Mourinho ample amount of tactical options, for example he can bring on Ivanovic for Right Back and move Dave Left Back if Filipe is tiring. Kurt Zouma can also operate as a full back if required on either sides.
Chelsea are a little stretched in defense if there is a case of injury or lack of form. But with quality players and also versatile midfielders like Ramires and John Obi Mikel, Chelsea can work out something during emergencies. Also young Nathan Ake and Andreas Christensen can be used in emergencies, but they aren’t first team regulars.