Real Madrid star Cristiano Ronaldo says comparisons between Barca's Lionel Messi and him get old, but he thinks he's the best player at the moment.

"You cannot compare a Ferrari with a Porsche because they have different engines," said Ronaldo in a CNN interview. "He does his very best for Barcelona and I do my best for Real Madrid."

Ronaldo scored 46 goals to lead Real Madrid to La Liga title. Messi broke the Spanish league scoring record with 50 goals for second-place Barca.

The Portuguese star said his miss in the penalty shootout that knocked Real Madrid out of the Champions League in the semifinals against Bayern Munich was one of the worst days of his career.

"It is always hard to lose, and especially when you do so on penalties," admitted the 2008 Ballon d'Or winner. "I am not too worried because I still scored that day [twice, in regulation time] but it is true that it was one of the worst days of my career."