Real Madrid forward Kylian Mbappe has suffered a thigh injury just before this weekend's La Liga clash with Atletico Madrid, according to his club's announcement on Wednesday.

The French ace was substituted during the 3-2 victory against Alaves on Tuesday and seemed to be in some pain. Spanish media reports indicate that Mbappe could be sidelined for approximately three weeks.

"Following examinations conducted today by Real Madrid's medical team on our player Kylian Mbappe, he has been diagnosed with an injury to the biceps femoris in his left leg," the Spanish champions stated in an official release.

Mbappe scored a remarkable goal in the thrilling encounter at the Santiago Bernabeu against Alaves and has already found the net five times this season in seven league outings. When asked about Mbappe's condition post-match, Real Madrid manager Carlo Ancelotti commented: "He's okay, just a bit tired, he requested the substitution to prevent any further issues."

Madrid, trailing leaders Barcelona by a point before the Catalans' match against Getafe on Wednesday, will travel to the Metropolitano stadium on Sunday to take on their rivals Atletico. Los Blancos have remained undefeated in La Liga for 39 games, since their loss to Atletico a year ago.

The striker is also expected to miss the upcoming Champions League match against Lille next week and potentially the Nations League games in October against Israel and Belgium with France.

Mbappe joined Real Madrid this summer after his contract with Paris Saint-Germain expired, realizing a long-held ambition. The 25-year-old has hit his stride in recent matches after a few initial games to adjust to life in the Spanish capital.

Mbappe has scored seven goals in nine appearances for Real Madrid across all competitions, including a goal in the UEFA Super Cup win over Atalanta in August and on his Champions League debut.