The Telegraph says Azpilicueta clashed with out-of-favour team-mate Rudiger 'on more than one occasion' as tensions flared between players prior to the sacking of Frank Lampard.
One of Lampard's biggest issues was his inability to trim his squad to make room for new signings Timo Werner, Kai Havertz, Ben Chilwell, Edouard Mendy and Thiago Silva.
The bloated squad saw Rudiger, Marcos Alonso and Jorginho given a stay of execution despite all three being players Lampard wanted to offload.
All three are believed to have 'caused issues' for the Chelsea boss prior to his sacking.
Azpilicueta as captain 'attempted to ease tensions' between players with academy stars also said to have been upset at their treatment amid claims of favouritism under the now-departed Lampard.