German top-flight team FC Cologne said on Friday that three people at the club had tested positive for COVID-19, but that they plan to continue training.
In a statement the Bundesliga side said the entire squad and coaching staff had been tested on Thursday.
"Three people tested positive, all are symptom free," the club statement said. "After an assessment of the cases by the responsible health authorities, the three people who tested positive will go into a 14-day quarantine at home."
Cologne said they would not confirm any names out of respect for the privacy of the individuals involved.
While Bundesliga clubs have returned to training, they must wait another week to find out about a possible restart to the season after the German government on Thursday delayed any decision over a league resumption amid the coronavirus pandemic.
The cash-strapped clubs and league had been hoping for the government to give the green light and end a two-month suspension, but Chancellor Angela Merkel has said any decision on if and when sports could resume would be taken on May 6.
If German football does return this month, it would almost certainly be weeks ahead of other major European leagues, with the Dutch Eredivisie and France's Ligue 1 having already called off the remainder of their seasons.
Tim Meyer, who chairs the German Football League's taskforce on coronavirus, said the positive tests didn't undermine the league's approach.
"We now see in everyday life that our concept recognises and reduces risks at an early stage," he said in a statement on Cologne's website.
"We will always be in close contact with the responsible health authorities and medical experts. We are convinced that with our concept, we can enable players to practice their profession with the best possible protection against infection."
Germany has suffered over 6,500 deaths from coronavirus with more than 162,00 people infected.
Information from Reuters and the Associated Press was used in this story.