Zidane took charge of Real Madrid's first team at the start of 2016, and the 44-year-old has led Los Blancos to back-to-back Champions League titles, in addition to wresting La Liga away from Barcelona last term.
Le Graet has claimed that he 'cannot believe' how much success Zidane has enjoyed in a short space of time, and he has backed the former midfielder to "one day" take control of the national team.
"That is a logical continuation. It is likely that one day he will be interested," Le Graet told RMC. "For the moment I think he still has a lot to give to Real and the club suits him perfectly.
"I can't believe what he is doing. I spoke to him two or three years ago, and at the time I was strongly advising him to go to Bordeaux or somewhere else, to start his career at a Ligue 1 club or somewhere more modest."
Zidane scored 31 times in 108 caps for France between 1994 and 2006.