France coach Didier Deschamps said it would have been "pointless" to leave a fatigued Kylian Mbappe on for the final 15 minutes of extra time against Portugal. (More Football News)
Mbappe was taken off at the interval in the added 30 minutes in Hamburg on Friday, with the score level at 0-0.
It remained that way 15 minutes later, though Portugal squandered two golden chances, with Joao Felix and Nuno Mendes failing to convert.
France ultimately got the job done in the end, though, triumphing 5-3 on penalties, with Joao Felix missing the decisive spot-kick.
Mbappe had a game-leading five shots, though they accumulated just 0.17 expected goals (xG), but Deschamps believes it would have been foolish to leave the 25-year-old on any longer.
Deschamps said: "He's tired, obviously. Muscularly, it's not easy with everything he's had.
"I saw him struggling during the first period of extra time. It was pointless.
"Kylian has always been honest with me and the group, so it was only natural to bring in some new blood."
Despite not scoring from open play so far at Euro 2024, France have now reached the semi-finals in four of the last five major tournaments. They will face Spain in Munich on Tuesday.
"It was a very tense, tight game," Deschamps said.
"It could have gone either way, even if we had a more difficult end to the game in extra time. Maybe we were a bit more tired. It comes down to details.
"I'm very happy for the squad, who played to the limit. We're going to enjoy being in the last four.
"It's becoming a habit but we mustn't trivialise it. It's to the credit of the whole group, those who play and those who can't."
Deschamps was left frustrated that he was not allowed to introduce Olivier Giroud, France's record scorer, for the shootout, though.
He added: "I couldn't bring Olivier on. The referee didn't take our request into account. I had this last change to make, and Olivier was a candidate to take the kick.
"There was a kind of tranquillity, [however], even if it was in front of the Portugal end."
