France head coach Guy Noves says his younger players looked "35" as they struggled to a 23-21 victory over Italy in their Six Nations opener in Paris on Saturday.
Jules Plisson's mammoth penalty clinched a hard-fought victory for Noves' men, sparing the blushes of original kicker Sebastien Bezy, who missed with all three of his attempts.
And, while he was able to take some positives from a performance that saw France score three tries, Noves - who took over from Philippe Saint-Andre after the Rugby World Cup - acknowledged his players need to show significant improvement over the remainder of the tournament.
"Despite a very short training period ahead of the game, we managed to win and with a very refreshed team, so the boys showed a lot of enthusiasm," he told a news conference.
"However, we did not always play with a clear head and there were no rhythm changes.
"We did not play fast enough. I had the feeling that players aged between 20 and 29 were actually 35, so we will have to talk about this.
"It is good to take risks, but you have to be intelligent too, that is to find the balance between the will to play and managing the game."
One of the positives for Les Bleus was the performance of Virimi Vakatawa - the Fiji-born sevens specialist touching down on his debut for the national team.
"He lived up to our expectations, shook his opponents and did not overthink it for his first game," added Noves. "I hope he will continue to improve."
France next face Ireland in Paris on February 13.