Captain Gonalons was reportedly on the verge of moving to Serie A side Napoli before Lyon chairman Jean-Michel Aulas pulled out of negotiations.
Garde believes Gonalons remaining at the Stade de Gerland serves as a major boost for Lyon's hopes for the remainder of their Ligue 1 campaign.
"What I can tell you is that of course I'm very happy he's staying here," Garde said.
"The team without Max, isn't the same.
"The possibility of having a good second half of the season and moving towards the objectives we set at the start of the season, it's clear to the president and myself we have more chance of doing that with Max in the team. It's as simple as that."
Lyon, 10th in Ligue 1, have endured a mixed season that has seen them bow out of the UEFA Champions League in the play-off stage to Real Sociedad.
However, Garde's men progressed top from Group I in the UEFA Europa League and remain in both the Coupe de France and the Coupe de la Ligue.
