Les Bleus were top of the Six Nations table with one game to play against Ireland when the tournament was halted because of the coronavirus pandemic in March.
An inexperienced France team had started the Fabien Galthie era in style by beating England and was on course for a Grand Slam before losing to Scotland at Murrayfield.
France fans have been starved of success in recent times, with their last Six Nations title coming a decade ago.
Clerc is optimistic about the future, but stressed the importance of patience.
Reflecting on the Six Nations performances, the former France wing said: "It was nice to watch. It is enjoyable, we wanted to see them winning. They started very well against England and lost one game.
"We are getting excited with this team and that's normal because we know they are very talented, they have a good team spirit, the players want to be together and play for each other. There is a solidarity between the players, so we like them.
"But we have to be patient. They are young players, they can make some mistakes, there will be some defeats. We said many good things about them, but there are some difficulties, we can't be too severe.
"We have to give them some time to grow. They have a good potential and a great team spirit. It was what we were expecting. The team spirit and the values of this team were important in the last Six Nations, maybe more important than the performances on the field."
Clerc says France must show more proof that it can step up against high-quality opposition before the next Rugby World Cup.
"I think they have to be ready before 2023, 2023 is the final goal. I think that many players, who are now in the French national team, will play several [Rugby] World Cups," he added.
"I think this team has to be stronger and stronger to be at 100 per cent in 2023. That also means that, in the meantime, they have to win Six Nations, they have to win friendly games in November or in the summer, they need to win against teams from the Southern Hemisphere.
"It will be important, they have to learn. There will be some ups and downs in the next years."