Azpilicueta had to leave the match on a stretcher and was breathing with the help of oxygen after being kicked in the face after a failed attempt at a bicycle kick from Southampton’s Sékou Mara.
According to Chelsea, the 33-year-old Spanish defender has suffered a concussion.
“The club’s medical team is keeping a close eye on Cesar and he is following the important regulations regarding concussions. Cesar watched training today before he starts working to get back on the football field,” writes the club.
Azpilicueta joined Chelsea in 2012 and has helped the club win two Premier League titles and a Champions League title. He has been the team captain since 2019.