France secured their place in the last four by overcoming Paraguay before defeating Morocco, setting up a Tuesday showdown with Spain. Victory would send them into Sunday's final, where either England or Argentina await.
The centre-back had hoped to come up against several of his Bayern teammates during the competition, but that possibility disappeared after Germany suffered a shock Round of 32 defeat to Paraguay.
That unexpected exit denied fans a potential Round of 16 meeting between France and Germany, leaving Upamecano without the chance to face familiar club colleagues on the international stage.
Germany had fielded a Bayern-heavy starting line-up against Paraguay, with Manuel Neuer, Joshua Kimmich, Jonathan Tah, Aleksandar Pavlovic, and Leroy Sane all named in the XI.
"I wanted to play against Germany. Unfortunately, they're out. That's football. Now they have to keep their heads up and simply keep going," Upamecano told Sky Germany.
"I send my greetings to all the German national team players from FC Bayern. Once we're back at Bayern, we'll get back to work and give it everything we've got. And I hope we win everything."
Didier Deschamps' tenure as France coach is set to conclude with Saturday's FIFA World Cup third-place play-off in Miami after they lost to Spain in the semi-finals.
Spain reached their first FIFA World Cup final in 16 years after putting on a football masterclass to convincingly beat France 2-0 at the Dallas Stadium.
For decades, African football has been judged on its potential rather than its achievements.
Brighton have completed the signing of Croatia defender Luka Vuskovic from Tottenham Hotspur in a club-record deal worth up to 50 million pounds.
