Chelsea are said to be furious with Mason Mount after the midfielder was pictured having a kickabout with Declan Rice despite being told to self-isolate.
Following positive coronavirus test results for Arsenal manager Mikel Arteta and Blues winger Callum Hudson-Odoi, all Premier League matches have been suspended until April 4 at the earliest.
Hudson-Odoi's diagnosis led to Chelsea announcing that their players would be self-isolating in accordance with government guidelines.
However, according to The Mirror, Mount is under fire after being spotted taking part in a kickabout with West Ham United's Rice at Trent Valley near Barnet.
The report also claims that Rice will face no punishment from the Hammers, who are currently not being forced to self-isolate, and a spokesman for Chelsea reportedly said the club will remind Mount of his responsibilities.
The 21-year-old has registered six goals and five assists in the Premier League for Lampard's side this season.