Riquelme has been in outstanding form in the Copa Libertadores, helping Boca Juniors clinch the title while on loan from Villarreal.

Real Madrid winger Robinho said: "Riquelme is different - he is a great player and we have to respect him a lot.

"He needs special treatment, you have to be careful with him more than with any other player."

Argentina enter the tournament with a strong squad including Javier Mascherano, Juan Sebastian Veron, Carlos Tevez, Lionel Messi and Hernan Crespo, while reigning champions Brazil go to Venezuela with an understrength group - notably without Ronaldinho and Kaka.

Robinho, though, admits the Brazil players - who begin their Group B campaign on Wednesday against Mexico in Puerto Ordaz - are highly motivated to perform well in the tournament.

He said: "The Copa America is important for any player and my goal here is to play well and help the national team be champions."