Philip Lahm and Per Mertesacker retired from international duty after winning the 2014 World Cup. PATRIK STOLLARZ/AFP/Getty Images

DFB director of sports Hansi Flick said that it would be against the Olympic spirit if players like Phillip Lahm, Per Mertesacker or Miroslav Klose would be included in the German football team for Rio 2016.

Lahm, Mertesacker and Klose -- all of whom retired from international duty after being crowned World Cup champions in 2014 -- reportedly were considering a comeback at next year's Olympic Games, which uses under-23 squads with the exception of three older players.

"They are without a doubt great players," Flick said in Frankfurter Allgemeine, "but I don't think that a comeback like that would be in accordance with the Olympic spirit."

Germany had qualified for Rio by reaching the semifinals of the European Under-21 Championship in June, where Germany lost 5-0 to Portugal.

"Maybe the pressure was too high," Flick said of the defeat. "Everybody said this is one of the best U21 teams we ever had."

But Flick also thinks that it might have been a mistake to make the German title ambitions public before the tournament.

"Maybe the team was a little overconfident," he said. "You have to be there on point and that was not the case from the beginning at this tournament."

"I still believe in the quality of the team and Horst Hrubesch's work," Flick added. "And just as much how they dealt with the defeat."

Flick was especially impressed by Liverpool's Emre Can reaction after the match.

"You have to raise your hat to Emre Can, how self-critical he reflected his performance after the defeat against Portugal," Flick said. "Everybody said in advance that he is strong, he is great. Maybe that was too much premature praise."

But Flick is not willing to lower the team's ambition, adding: "If we go to the Olympics we want to win the gold medal."