Werder Bremen have confirmed one of their players has been placed in a two-week quarantine a day before the Bundesliga is set to resume.
Football in Germany's top flight is set to return on Saturday, having been suspended since March as a result of the coronavirus pandemic.
Werder explained the unnamed player has not tested positive but that a member of his "personal circle" has contracted COVID-19.
A statement read: "A member of the SV Werder Bremen first team has been placed under a two-week quarantine, after a member of his personal circle tested positive for COVID-19 earlier this week.
"Although the player himself tested negative during all previous rounds of testing, the decision to place him under quarantine was made in conjunction with the Bremen health authorities.
"The player has since tested negative on two occasions."
Sporting director Frank Baumann added: "As a result, our team and our staff are not under any risk. This shows that the medical protocol is working and that infected individuals can be identified early on in order for the necessary measures to be implemented."
The Bundesliga is due to be the first of the major European leagues to resume since being halted due to the coronavirus crisis.
Bremen, who are 17th in the table, are scheduled to face Bayer Leverkusen on Monday.