Players are returning to the Bundesliga from international duty, and they are bringing the coronavirus with them.
Hoffenheim played Borussia Dortmund on Saturday without Andrej Kramaric and Kasim Adams after they tested positive following national team matches with Croatia and Ghana, respectively. Czech Republic defender Pavel Kaderabek was in quarantine because of a family member's result.
Hoffenheim director of football Alexander Rosen said after the 1-0 loss that clubs would have to think about letting players leave again for international duty.
"The clubs pay the players and work with everyone to ensure the processes are carried out properly," Rosen said. "And you get the impression that the national associations simply don't care."
Dortmund had to do without defender Manuel Akanji after he tested positive while on duty for Switzerland.
"When you look at the rising numbers, you have to wonder whether it makes sense to stop (players from leaving) for the next break," Leipzig sports director Markus Krösche said after his team's 2-0 win in Augsburg. "There has to be clear guidance from FIFA on how it goes, especially in risk areas."
Leipzig was without Amadou Haidara. The midfielder had tested positive after helping Mali defeat Ghana 3-0 in a friendly in Turkey. Also, Hertha Berlin was upset that Mattéo Guendouzi returned from France's under-21 team with the virus.
"The signing was already very complicated," Hertha coach Bruno Labbadia. "Now it's the worst case scenario."
Other cases are causing concern that soccer may be put on hold again as Germany appears to be dealing with a second wave of the virus. The country's disease control center reported 7,830 new cases over the previous 24 hours on Saturday, a record for the third day in a row.
Second-division club Nuremberg reported two positive cases on Wednesday. The game between Osnabrück and Darmstadt was postponed with most of the home team in quarantine for 14 days after two of its players tested positive for COVID-19.
Union Berlin striker Max Kruse was criticized for posting an Instagram video showing him enjoying a visit to a shisha bar with friends. Berlin has some of Germany's highest virus infection rates.
"It wasn't the cleverest from Max, he knows that himself," Union teammate Marvin Friedrich said after the team's 1-1 draw at Schalke on Sunday.
Dortmund coach Lucien Favre assumes there will be more cases among players and he warned that the league may be suspended again. There was no soccer for two months when the pandemic started in March.
"We have to keep trying to play as long as we can," Favre said Saturday, adding that traveling was generally bad for the situation.
German Chancellor Angela Merkel was at the same time urging people to slow the spread of the virus by avoiding unnecessary travel and remaining home whenever possible.
The Champions League starts Tuesday with teams flying all over the continent.
Dortmund will visit Lazio for its Champions League opener in Rome. Bayern Munich has games at Lokomotiv Moscow and Salzburg, Borussia Mönchengladbach visits Inter Milan and Shakhtar Donetsk, and Leipzig travels to Manchester United before the next international break in November.
More infected players could increase the pressure on politicians to be seen to be taking action.
Dortmund chief executive Hans-Joachim Watzke on Saturday criticized officials for what he called "populist soccer bashing."
Most Bundesliga games took place without fans or with very few supporters attending over the weekend, and it appears the situation will remain for some time. Clubs are already struggling because of lost income from ticket sales.
"It has to go on," Watzke told broadcaster ZDF. "We need these ghost games (without fans) at least. If we also don't have those, it will get very tight."