Liverpool star Kostas Tsimikaswill likely miss a number of games after testing positive for Covid-19.
The Greece international signed from Olympiakos earlier this summer and still stands as the only arrival at Anfield.
He has joined to provide competition at left-back, where Andy Robertson was the club's only recognised player there.
With Greece preparing to take on Slovenia in the Nations League, the defender flew out with the squad.
However, the news that he has contracted the disease will hit Liverpool hard.
The Premier League will prepare to start this month and the Reds are looking to defend their crown.
They face newly-promoted Leeds United in a mouthwatering opener on September 12.
Tsimikaswill definitely miss out on the clash, though, and could also be absent for the following fixture against Chelsea.
However, he might be available for the next match against Arsenal - which will go ahead of September 28.
A statement from the Hellenic Football Federation read: "The Greek Football Federation was informed today of a positive COVID-19 sample on the results of checks carried out by the authorised by UEFA medical service among members of the mission of the national men's team, which is located in Ljubljana and preparing for Sunday's match with Kosovo in Pristina.
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"UEFA's protocol is being adhered to and EODY [Hellenic National Public Health Organization] as well as the GGA health committee were immediately informed.
"The member of the squad who had a positive sample and was isolated for the last 36 hours for precautionary reasons from the other members of the squad, leaves the team tomorrow morning, while the preparation of the Greek team continues.
"The other members of the squad underwent a new test today in accordance with the UEFA protocol and the results will be announced tomorrow before the departure of the team to Kosovo."