Kylian Mbappé was substituted because of an injury during the first half of Real Madrid's Champions League clash at Atalanta on Tuesday, minutes after scoring his 50th career goal in the competition.

The France forward was substituted in the 35th minute after he went down with a non-contact injury, although he was able to walk off on his own. Rodrygo came on in his place.

A source has told ESPN that Mbappé felt discomfort in his left thigh and will undergo tests on Wednesday.

"[Mbappé] has a strain, some discomfort in his thigh," Ancelotti told Movistar after the match. "We'll have to see. It doesn't look serious, but I don't know, we'll see tomorrow. He couldn't sprint. It was bothering him, so we had to substitute him.

Madrid went onto earn a 3-2 win after second-half goals from Vinícius Júnior and Jude Bellingham.

Until he came off, it had been an excellent night for Mbappé.

He used an expert piece of control with his left foot to gather a pass from Brahim Díaz before he quickly darted past a defender and unleashed a shot with his right foot into the far corner after just 10 minutes.

"I gave him a hug, but I have no idea [about his injury.] We hope it isn't anything," Díaz told Movistar.

The goal meant Mbappé reached the 50-goal milestone in 79 matches -- the fourth fastest in Champions League history after Ruud van Nistelrooy (62 games), Lionel Messi (66), and Robert Lewandowski (77).

Cristiano Ronaldo leads the all-time Champions League scoring list with 140 goals, and Messi is next with 129.

The victory against Atalanta was only Madrid's third win in the competition's revamped league phase and leaves the 15-time champion in the unseeded playoff positions in 18th place.

"An important win, with the three points and for morale, going into Christmas. We're getting players back, Vini played today, Rodrygo played, we'll get Camavinga back. We have to hang on until Christmas,"Ancelotti said.

"We could get into the top eight [in Champions League standings]. The objective is clear, we have two games, and we have to win both."

Information from the Associated Press and ESPN's Rodrigo Faez and Gab Marcotti contributed to this report.