The 18-year-old was an unused substitute for the champions' 4-1 victory on Sunday that saw them keep up their winning start to the Ligue 1 season.
Mbappe's exclusion from the starting XI has led to further speculation that his days at Monaco are numbered, but Jardim insisted that it was more a case of resting legs.
"It's a club decision not to have him start the game," Jardim told a news conference following the match.
"In the end, the game went smoothly and I gave the opportunity to other players to help make the building of the team more effective.
"In the coming months, with the Champions League, we'll need everyone. We have to give rhythm to those who aren't often used."
Paris Saint-Germain are heavily rumoured to be on the verge of signing Mbappe.