The Champions League and La Liga are different competitions, so the fact that Mbappe received a red card in a La Liga game will not affect his participation in the Champions League.
This is not a necessary red card.] and even this is his first red card at Real Madrid and his first red card after 6 years, the last one was in the Coupe de France match in 2019. Yes, and fortunately, Real Madrid had led 0-1 just before the red card happened.
This will be quite bad for Real Madrid's performance going forward with Mbappe's absence for several matches. But as you said, La Liga matches are different from UCL, so red cards in La Liga do not apply in UCL and Mbappe can still be in the UCL lineup when facing Arsenal later.
Source: Mbappé sees red
Mbappe only got one game of disqualification, essentially did not suffer from this red in any way, as he will be ready to go out for all important games. If it was a disciplinary violation, then the punishment would be from 3 to 5 games, but it was just in game violation. By the way, I didn’t see the game, but I saw screenshots where the Alaves players also walked with straight feet at the Real players, but the referee didn’t even give a foul. To be honest, I am increasingly inclined to believe that there is a conspiracy against Real in La Liga
