With the entire team forced to self-isolate for a fortnight, the relegation-threatened club will have to reschedule their trip to Mainz on Sunday, a home game against Freiburg next Wednesday and the visit to bottom side Schalke on April 24.
“That is the right step from a health perspective, but it is obviously a blow from a sporting perspective,” said Hertha sporting director Arne Friedrich.
After coach Pal Dardai, assistant coach Admir Hamzagic and Belgium striker Dodi Lukebakio returned positive tests on Thursday morning, Hertha initially planned to isolate together as a team in a local hotel, leaving only for training and matches.
That idea was torpedoed by Plattenhardt’s positive test, with local health authorities imposing what Hertha called “stricter measures”.
Friedrich said the team would hold “virtual training sessions” at home in a bid to stay fit for the rest of the relegation fight.
Yet the outbreak also provides the Bundesliga with a scheduling headache, with the German Football League (DFL) under pressure to complete the season by the end of May before players leave for the European Championships in the summer.
Similar outbreaks had already plunged the second division into chaos this month, with three clubs in self-isolation and unable to play.
Yet DFL president Christian Seifert said there was time to reschedule all postponed games.
“In my view, there is no reason to think about suspending the season at the moment,” he told Bild newspaper.
He added that the league could “rethink” if the situation changed over the next two weeks.
In a statement, the DFL said it would announce new dates for the postponed Hertha games “in the coming week”.