Los Blancos were widely expected to sign Mbappe on a free transfer this summer, but the France international spectacularly announced on Saturday that he has penned a new deal in Paris until 2025.
Real Madrid had allegedly been certain that they would be signing the World Cup winner ahead of the 2022-23 campaign, prioritising the 23-year-old over Erling Braut Haaland, who has now agreed to join Manchester City from Borussia Dortmund.
The report claims that Los Blancos are now planning to accelerate their pursuit of Tchouameni, as they fear also missing out on the Frenchman this summer.
The 22-year-old enjoyed an impressive 2021-22 campaign for Monaco, scoring five goals and registering three assists in 50 appearances in all competitions.
In Ligue 1, he provided three goals and two assists in 35 appearances, as the principality outfit finished third, which has seen them book a spot in next season's Champions League third qualifying round.
However, Tchouameni recently insisted that he was not in a rush to leave Monaco despite the widespread speculation surrounding his future.
"I have a contract until 2024, with an option until 2025. We will see what the future holds for me," the midfielder recently told reporters. "A lot of things can happen in the transfer window. There is my case and that of the other players, some of whom are at the end of their contracts and have other desires elsewhere.
"Why not stay in the Champions League? Being eliminated by Shakhtar Donetsk in the preliminary round this season stuck in my throat. Playing in the Champions League with Monaco is not something that would displease me."
Since arriving at Stade Louis II from Bordeaux in January 2020, the midfielder has made 95 appearances for the Ligue 1 side, contributing eight goals and seven assists in the process.
Real Madrid completed their La Liga season with a goalless draw against Real Betis on Friday evening and are now preparing for the Champions League final against Liverpool next weekend.