Hertha Berlin are in the middle of an unlikely injury crisis, with five goalkeepers injured and under a month to go until the new Bundesliga season kicks off.
United States youth international Jonathan Klinsmann is among them with a patellar ligament injury.
That means that under-17 keeper Luis Klatte is currently deputising with the senior team.
"We must be jinxed right now," Hertha coach Pal Dardai told reporters on Thursday, adding that 65-year-old squad manager Nello Di Martino was already prepared to train with the team.
But while first-choice goalkeeper Rune Jarstein is likely to return in Friday's test match at Anker Wismar following an infection, Klinsmann could be set for a longer spell on the sidelines.
"It can take three days or it can take a very long time," Dardai said of Klinsmann's patellar ligament irritation.
The 20-year-old son of former U.S. head coach Jurgen Klinsmann joined Hertha following a successful trial with the club earlier this month.
He is expected to win regular minutes for the club's under-23 team in the regional fourth division to gain experience, but will train with the senior squad.