The 1978 World Cup winner believes his compatriot is no longer as lethal and ambitious as a few years ago, saying he is “one-and-a-half gears below his best”
The 27-year-old had to settle for second spot in the Fifa Ballon d’Or vote behind Ronaldo last year and the Portugal star is once more the favourite to win the prestigious individual award for 2014.
Kempes feels Messi is no longer the clinical finisher he was before, although he has stressed his compatriot remains arguably the best when it comes to creating chances.
“Messi is not at the peak of his game at the moment. He’s not like a few years ago,” Kempes told AS.
“I think he’s one-and-a-half gears below his best. And that’s the difference between Real Madrid and Barcelona right now.
“At this stage, Ronaldo is more hungry for success than Messi.
“Messi is not as clinical as he was two or three years ago. We should not forget, however, that he has been playing a bit deeper recently to give that final pass. And he is still the best when it comes to that.”
Messi has scored 11 goals in 15 appearances in all competitions for Barcelona so far this season.