Dean Smith says the "uncontrollable" coronavirus outbreak which caused two of Aston Villa's league games to be postponed is a warning to other clubs.
Villa have not played for 19 days after two Premier League games were postponed when several players and staff tested positive for Covid-19.
"It is a warning and it was certainly a warning to ourselves," Smith said.
"You're worried about anything you touch after that because you can see how rampant it is."
Smith would not name which players had caught the virus and who was still struggling, but said his team selection for the trip to Etihad Stadium would be "affected".