Former Barcelona midfielder Deco believes comparisons made between Lionel Messi and Cristiano Ronaldo are not fair on either player.
The Clasico rivals are widely regarded as the two greatest players in the world, but the former Portugal international believes trying to choose between them is impossible.
Having played with both during his career, Deco believes they have very different characteristics that separate them from other players in the game.
"It is a privilege to have played with both of them," he told Perform.
"But I think it is unfair to compare as they have different styles, and are so good with their styles, that it would be unfair to judge who is better.
"Last year, Cristiano was better in the first six months, I mean he had better numbers, but in the final part Messi got better numbers."
Deco was the man replaced by Messi when the Argentine made his Barcelona debut in 2004 and believes that the club's record goalscorer has taken the Catalan side to another level.
"I saw Messi growing at Barcelona," he added. "[He] is the cherry on top of the cake. Messi is able to make this already very good team be something else."
Deco's international career with Portugal also coincided with the debut of a young Ronaldo and the Fluminense playmaker highlighted the Real Madrid star's mental fortitude as a key reason for his success.
"He impressed me with his winning mentality since he was very young," Deco continued. "He is an example of a person who overcame [problems] and we must admire this.
"He has a winning mentality that honestly I have never seen. I have never met a player even close to the mentality that the one he has."
The Brazilian-born midfielder returned to the country of his birth in 2010 and dismissed claims that the 2014 World Cup could ultimately prove detrimental to the nation.
He explained: "Obviously people will always question if it's worth spending money to host big events. It is complicated.
"But I think these events benefit the country. I experienced this in Portugal in 2004 and saw how important it was.
"And then we need to know if the legacy will remain or not. The event itself is good, but how it will be administered afterwards is another issue."