Simon went off injured in the 43rd minute in Nantes 3-3 away draw against Dijon.
Before he was replaced, he was on target to make it 1-1in the 10th minute.
Speaking after the game, Gourcuff said: “His (Simon) exit affected us. Regarding all injuries in the defensive sector, it’s incredible. I hope to have feedback this week.”
Simon has now scored nine goals, eight assists in 26 appearances in all competitions this season.