The 21-year-old, who has played at every France youth level up until the Under-21s, has impressed while Gourcuff recovers from an injury that could keep him sidelined for a further three weeks.
Formerly of Bordeaux and Werder Bremen, the 17-times capped Micoud is of the opinion that Grenier ought to retain his place in the Lyon squad even once Gourcuff, 26, returns to full fitness.
He told French newspaper L’Equipe: “Grenier affects the play three times more than Gourcuff and is injured 10 times less.
“Seriously, this is a true playmaker who, with his technical quality and his vision, knows how to play the opposition.
“He has the ability to find the perfect pass when there is movement around him.
“And [he has shown] since the beginning of the season, he can be decisive. I love this kind of player - he is what I like in football.”