Questions have been raised about restarting the German football season in May after three people at the FC Cologne team tested positive for COVID-19.
In a statement, the club said three people tested positive after the entire team and coaching staff underwent COVID-19 screening.
The three - who are all symptom free - will be placed under 14-day home quarantine.
"Cologne will not confirm any names out of respect for the privacy of those affected," the club added in their statement.
While Bundesliga clubs have returned to training in small groups, it will take another week until an official announcement about the football season will be made.