Left back: Marcos Alonso
Manchester United's Luke Shaw has come of age this season, realizing his immense potential he was always touted of. However, his Chelsea rival Alonso isn't only having a fine season of his own, but has even registered greater numbers. He has made more interceptions (32 to 21), more tackles (66 to 54) and more clearances (73 to 71). And despite that, his offensive play is no half-shabby either, scoring once and assisting four more.
Centre-back: David Luiz
The Brazilian had made a successful return to the EPL in 2016, and even today, remains an important figure at the heart of Chelsea's backline. Although slightly error prone, Luiz commands his area with great authority and has been on his toes to sniff any danger. He's made 133 clearances whilst also posting a 74% tackle success rate. The 2,390 passes he's laid so far ranks fifth best in the league, as we have also got to see the offensive side of him more this season - scoring and assisting twice each so far.
Centre-back: Chris Smalling
Now in his ninth season with the Red Devils, Smalling continues to be a vital part of the Manchester United defense, though he's blown hot and cold this season. On many occasions, he has justified Mourinho's demand for a world-class centre-back, but did appear to conjure his better self during the early, barnstorming days of Solskjaer's tenure. Smalling doesn't shy away from tackles and is never afraid to put his body on the line to prevent danger. It's his robust self which would help the hosts in a big game like this.
Right back: Cesar Azpilicueta
The Spanish fullback has taken to the mantle of captaincy by storm, and has led by an example from the back. He's made 93 tackles and also laid 2,263 passes so far - both of which rank within the top 10 on the respective lists. But Azpilicueta has also magnified his attacking penchant, charging forward at every given opportunity: he has laid six assists and also has a goal to his name, adding another dimension to Chelsea's attack.