Chelsea's Callum Hudson-Odoi has tested positive for coronavirus.
The entire Chelsea squad has gone into self-isolation as a result, a club statement said on Friday morning.
Hudson-Odoi displayed symptoms earlier this week and has since stayed away from the club. His test result came back positive on Thursday evening, making him the first Premier League player known to have contracted the virus.
The club's statement read: "Chelsea men's team player Callum Hudson-Odoi had a positive test result for coronavirus returned this evening.
"Chelsea personnel who had recent close contact with the player in the men's team building will now self-isolate in line with Government health guidelines.
"These will include initially the full men's team squad, coaching staff and a number of backroom staff.
"It is expected that those who did not have close contact with Callum will return to work in the coming days. In the meantime, the men's team building, one of several separate buildings at our training ground, will remain closed.
"The rest of our training facility, Stamford Bridge and our other facilities are operating as normal."
The news comes just hours after Arsenal manager, Mikel Arteta, also tested positive for coronavirus and the entire Arsenal squad went into self-isolation. The Gunners' match against Brighton this weekend has been postponed.
Chelsea face Aston Villa on Sunday and their statement added: "We will continue to adhere to Government and Public Health Guidelines with regard to our facilities and staff and will be discussing next steps with regards to upcoming fixtures with the Premier League on Friday morning."
Surely the Premier League have to postpone all matches now!News Now - Sport News