West Ham United manager David Moyes and two of the club's players have tested positive for coronavirus.
The Premier League club were informed of the positive tests while preparing for Tuesday's Carabao Cup tie against Hull City at London Stadium.
Moyes, 57, defender Issa Diop, 23, and 24-year-old midfielder Josh Cullen will now be required to self-isolate.
"The manager and both players immediately left the stadium and have returned home," said a club statement.
West Ham said the three men were all asymptomatic and assistant manager Alan Irvine took charge of the Hull match, which both Diop and Cullen were due to start.