Former Denmark international midfielder Thomas Kahlenberg has tested positive for coronavirus and his former club Brondby said 13 members of its staff had been put into quarantine as a result.
It has been reported that several members of Dutch club Ajax's backroom staff are also in quarantine, having been in contact with 36-year-old Kahlenberg when he visited Amsterdam where he caught the virus.
"On a recent trip to Amsterdam Thomas contracted coronavirus. He is now in isolation," Copenhagen-based Brondby said in a statement.
Kahlenberg, who made the last of his 47 appearances for Denmark in 2014, is believed to have been in contact with 13 members of Brondby's staff, including one player and an assistant coach.
Brondby have appealed to supporters of the club who have had contact with Kahlenberg to report to health services.
Denmark has reported 20 cases of coronavirus.