The 35-year-old played alongside the Portuguese international during his time at the club and came up against the Barcelona star on a number of occasions.
"I think both Messi and Cristiano are great players, but Messi is better," he is quoted as saying by Punto Pelota.
The 35-year-old is excited about this weekend’s clash between his former club and Barcelona but warns that Real must get something from the game due to the gap between the two sides in the table.
"For Barcelona there are three points at stake, and for Madrid it is a final, because if you lose its 11 points difference," he added.
The recently retired Spaniard also claimed that he was close to signing for River Plate before deciding that staying in Spain would be best for his family.
"I was 99 percent going to play for River, but my wife and I thought about the situation and decided it was not convenient. Argentina is far away and she is pregnant and needs to be close to her family," he concluded.