Officials are worried that Germany's future Steffi Grafs and Dirk Nowitzkys may not have the same chance to become world-class athletes because of longer school hours that have cut into afternoon sports.
Under pressure to make life easier for working parents, schools across Germany are gradually beginning to extend the school day until around 3:30 or 4:00 pm for children from the age of six, replacing the long-held school-bell hour of 12:30 or 1:00 pm.
AdvertisementOfficials from the sports world are worried about the long-term impact in a country that traditionally nurtures the stars of tomorrow on after-school playing fields and at Germany's sterling sports clubs.
"There is a huge danger for the sports associations if they don't manage to get really involved in schools," warned Georg Wydra, head of the Sports Science Institute at Saarbruecken University.
Most regional states, which in Germany bear responsibility for education, have reduced the upper-school leaving-age by one year, to bring German graduates in line with other European nations.
The move, however, requires some longer days to cover the curriculum.
"Sports associations clearly feel that pupils have less time," said Frank Obst of the western state of Hesse's sports federation.
Germany, which ranked fifth on the medals table at the 2008 Olympic Games, has 91,000 sports clubs. Obst stressed that they provide the foundation for the nation's sports scene.
Boris Rump of the German Olympic Committee said so far there had not been a strong fall in the number of youngsters taking part in sports, but said sports clubs must actively try to get involved in schools to survive.
One such example is a sports club in Berg, on the Swiss border, which provides afternoon table-tennis lessons to around 75 children from four different schools.
It had to employ someone to provide the coaching, which takes place at school and is funded partly with regional subsidies, said Gerhard Scheuing, who is in charge of the club's youth section.
"Schools are constantly on the lookout for interesting and varied activities to fill their curriculum," Scheuing said.
"And for us, our objective is to spot the children and inspire them to become a member," he added.
Admittedly, the club only recruited one new member through the scheme last year, but, Scheuing stresses, "the effect will be seen in the long term".
In practice, younger pupils rarely have afternoon classes anyway, and, if they do, they are not held five days a week, as afternoons are reserved for school sports or musical pursuits.
Officials also face challenges posed by shifting trends in the popularity of a certain sport, making it harder to attract children.
"Children are no longer coming to tennis, it's tennis which has to go to the children," lamented Michael Mueller of the German Tennis Federation, saying that unlike other sports, it had not developed a strategy for schools.
"If I'm looking for a new Boris Becker, he can't start playing tennis at the age of 15," he added.
Concerns are also rife that competing at a high level with the potential of becoming a top athlete will take a hit if new school timetables have to be accommodated.
"Regular training three or four times a week becomes very difficult to reconcile with school," Rump said.
Young talent that has already been identified can rely on a network of specialised schools with adapted hours, but the fear is that the earlier stage of spotting a child's potential risks being lost.
To recruit talent "you need a certain mass," Rump said.