Mason Mount will be reminded of his responsibilities by Chelsea after the England international broke his self-isolation at the weekend, the PA news agency understands.
The 21-year-old was spotted playing football with West Ham midfielder Declan Rice at a centre in London on Sunday.
It comes after Chelsea revealed in the early hours of Friday that winger Callum Hudson-Odoi had tested positive for coronavirus.
As a result, the full men's squad, coaching staff and a number of the backroom team were forced to self-isolate in line with government health guidelines.
Mount broke those self-isolation guidelines when he met up with Rice and will be reminded of his responsibilities by the Blues.
The Premier League is currently suspended until April 4 due to the coronavirus pandemic.