Real Madrid forward Kylian Mbappé has been ruled out for 10 days with a thigh injury, sources told ESPN on Thursday.

The France forward was substituted in the 35th minute of Tuesday's 3-2 win at Atalanta in the Champions League with a suspected left thigh problem.

The blow means that Mbappé will miss the LaLiga contest at Rayo Vallecano on Saturday and is a doubt for the FIFA Intercontinental Cup -- what used to be known as the Club World Cup before it was revamped into a 32-team competition set to debut in June.

Madrid qualified for the tournament by winning last year's Champions League.

The Intercontinental Cup final will be against either Mexico's Pachuca or Al Ahly from Egypt on Dec. 18 in Doha, Qatar.

Sources told ESPN that Madrid will not rush Mbappé back for the final, deeming it "counterproductive" to do so if it risks worsening the muscle injury.

"Following tests carried out on Kylian Mbappé today by the Real Madrid medical department, the player has been diagnosed with a thigh injury in his left leg," a club statement said. "His progress will be monitored."

Mbappé has scored 12 goals in 22 appearances for Madrid in all competitions so far since joining the club as a free agent in the summer after his contract with Paris Saint-Germain expired.

Despite his scoring form, Mbappé has faced criticism for his performances with Madrid suffering some high-profile defeats in the season, most notably losing 4-0 at home to Barcelona in the Clásico.

Real Madrid captain Dani Carvajal is convinced Mbappé will deliver titles for Los Blancos.

Carvajal, who is recovering from an ACL injury, said of the France star while attending an awards ceremony on Wednesday: "He's adapting very well. He's scored many goals with us despite the criticism he's received of his game. I hope he continues until the end of the season progressing, securing his place in the team. I'm certain he will give us titles."

Madrid are second in LaLiga, two points behind Barcelona.

As for the Champions League, with two games left in the league phase, Madrid are 18th in the 36-team table on nine points, three points off the top eight spots which secure direct qualification to the round of 16.