The Argentinian Football Association (AFA) announced their squad at the beginning of July and included the Barca forward.

However, the Games clash with the dates of the Champions League preliminary round and Barca insist they will do everything in their power to hold onto the 21-year-old.

Barcelona have been told Messi may be suspended for the duration of the Olympic tournament if he is not released, as FIFA rules state all players under 23 must be released by their clubs if called up to play.

But Puyol believes the loss of the South American at such a crucial time would be a blow to the club.

"We have a great squad, but nobody doubts that Messi is a massive player for us," Puyol told Spanish newspaper El Mundo Deportivo.

"In my opinion he is one of the best players in the world. I hope that everything gets sorted out quickly.

"We cannot control the situation, but I hope he can be here with us."

Messi is now the main star in the Barca squad following the departure of Ronaldinho to AC Milan last week.

The 28-year-old Brazilian failed to show his best form during a final troubled season at the Nou Camp, but Puyol still recognised the contribution Ronaldinho had made to the club in recent years.

"He has given us so much," he said of his former team-mate.

"He changed the situation of the club. He has been one of the best players to ever pass through Barcelona.

"I can only thank him for what he has given us and I wish him plenty of luck in Milan."