Cape Town - Paris Saint-Germain forward Kylian Mbappe believes it's ridiculous to suggest that Real Madrid superstar Cristiano Ronaldo is declining as a footballer.

Ronaldo was sensational last season, bagging 12 goals in 13 Champions League games and 25 in 29 La Liga appearances. This season, the Portuguese has not quite reached the same level, especially in La Liga where he has scored only eight goals in 17 games. 

However, Mbappe believes the five-time Ballon d'Or winner is just as dangerous as he's always been and has warned his PSG team-mates that he is still Real's biggest strength, ahead of the two teams' Champions League last-16 clash next week.

"It is ridiculous to talk about Ronaldo being in decline,” Mbappe told reporters, according to Marca.

"If he is in decline, I would not want to hear what you say about the rest of the players! Cristiano is a fantastic player but obviously, we hope he does not play at his best against us!

"But yes, for the Champions League game we will pay a lot of attention to him as we want to combat Madrid’s strengths and Cristiano is one of their key strengths."