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 which is why Barca are desperate to hold on to Messi.

With the wrangle over the Argentina star continuing, Messi returned to pre-season training on today, four days earlier than planned.

"We brought forward his arrival and now we are waiting for a statement from FIFA," said Guardiola.

"We are defending that which we think is right, and if they say we are correct, Leo will stay.

"If is doesn't turn out like that, he will have to go to the Games."

Barca's chances of preventing Messi from playing in Beijing appear slim. The player himself has said he wants to represent his country, while FIFA's rules stipulate that players under the age of 23 must be released from their clubs for the Olympics.

FIFA moved to clarify their position on the Olympics last week, issuing a statement that said all players 23 and under must be released.

"In view of the importance of the Olympic Tournament for the entire sporting movement in general and football in particular, as well as on the basis of customary law, the release of players younger than 23 has always been mandatory for all clubs. For Beijing 2008 the same principle shall apply.

"This is not a new position and the regulations have not changed."

Barcelona, meanwhile, are also trying to prevent Ronaldinho from playing. As the playmaker is aged 28, they have a right not to release him, but the player himself remains adamant he intends to play having been named in the Brazil squad.

By the time the Olympics begin, it may no longer be Barca's problem as Ronaldinho is up for sale and a move to either AC Milan or Manchester City could be completed this week.