Argentina have wheeled out the big guns as they seek to defend the Olympic title they claimed in Athens four years ago.

Lionel Messi, Sergio Aguero and Juan Roman Riquelme play alongside Liverpool's Javier Mascherano, one of three over-age players in the Under-23 tournament.

The 24-year-old defensive midfielder will be key for his side, with his experience in the Champions League, Copa America and World Cup likely to be vital.

Mascherano says: "Hopefully I will go to Beijing and win the gold for my country and come back and win the title with Liverpool."