The France captain has faced questions over his decision to recover from a left knee injury in France and Switzerland rather than remain in Madrid. Mbappe sustained the injury while playing for France against Turkey in the UEFA Nations League.
Photographs of the 27-year-old outside a Paris nightclub and riding a bicycle in Switzerland also sparked criticism from some supporters, particularly after Mourinho warned his players against activities such as cycling and skiing that could risk injury.
However, the Portuguese coach insisted Mbappe had fulfilled his responsibilities to the club.
"Are these criticisms over the top? They are ridiculous," Mourinho said at his press conference.
"All the players who were obliged to be present every day for their recovery were here. Mbappe came, like the others, to undergo scans in order to be diagnosed.
"He then went to see a specialist in France, because he has history with his knee which we cannot ignore."
Mourinho also challenged the claims surrounding Mbappe's off-field activities, explaining that the event in Paris was a private Fashion Week function rather than a nightclub outing.
He dismissed suggestions that the forward had been taking unnecessary risks on a bicycle in Switzerland, pointing out that the hotel provided bicycles for guests to travel between its accommodation and communal areas.
Mourinho said he was confident Mbappe had met his obligations to Real Madrid and played down the possibility of the striker receiving a hostile reception from supporters.
The controversy comes at a difficult time for Madrid, who trail bitter rivals Barcelona by seven points in the La Liga title race.
Mbappe has faced criticism from sections of the club's support before. Last month, the Ultras Sur supporters' group objected to his involvement in a gesture of solidarity with residents of Ceuta, the Spanish territory in North Africa that has been dealing with a migration crisis.
