The 20-year-old would miss the end of Barca's pre-season preparations as the Olympic competition runs August 7-23 and Fifa does not require club teams to release players but the Spanish giants have approved Messi's participation.

Messi is now set to return to South America for World Cup qualifiers against Ecuador and Brazil in June before traveling to China, where Argentina will be looking to defend the gold medal they won at Athens in 2004.

"I have everything arranged for playing in the Olympic Games," he told Radio La Red. "I want to travel to Argentina and start to work with the team.

"Argentina is capable of beating any team. Brazil have the best players in the world but I think that we can beat them in the South American qualifiers.

"I would like to have that chance so I can celebrate what I couldn't celebrate with Barcelona."

Barca will finish the season empty-handed for the second year running, which has led to the departure of Frank Rijkaard, with former Barca captain Josep Guardiola to replace him as coach.

Rijkaard was given a warm reception for his final home game in charge against Real Mallorca on Sunday after winning two La Liga titles and the Champions League in his five-year stint at Camp Nou.

And although it was another disappointing day for Barca as they lost their penultimate game of the season 3-2, Messi defended the outgoing coach.

"It hasn't been a good year for Barcelona," said Messi. "Our objective was to win everything but unfortunately we didn't win anything. It has been two years without winning a title and we feel that.

"I am very thankful to Rijkaard. Although we couldn't win a title, I think he has done his job correctly.

"I don't think he was the fault for what happened. The supporters know that and that's why they let him go in the way he deserved."

Messi has been linked with a move to England with Champions League finalists Chelsea but he insists he has no plans to leave Spain just yet.

"I am fine at Barcelona and if it's true what is being said about Chelsea, the only thing it makes me feel is pride," he added. "It's an honor for me that such an important team is interested."