Mbappe calls out Madrid fans after Vinicius jeered
Vinicius and Jude Bellingham came in for ire from the home fans after a disastrous week in which they lost to Barcelona in the Super Cup and second-tier Albacete in the Spanish Cup.
Madrid also fired coach Xabi Alonso last Monday.
"The fans shouldn't single out one individual to be booed, none of this is Vinicius' fault, it's all of our faults if we play poorly," said Mbappe.
"I didn't like that at all."
Mbappe described Vinicius, who narrowly missed out on the Ballon d'Or in 2024, as one of the best players in the world.
"We must protect him better so that he is not alone in the face of criticism. He is not alone at Real Madrid. We are all with him," said Mbappe.
Madrid host Ligue 1 outfit Monaco at the Bernabeu on Tuesday.
They closed to within a point of leaders Barcelona in La Liga this weekend after beating Levante 2-0 to record new coach Alvaro Arbeloa's first win at the helm.