Lionel Messi is yet to sign the new Barcelona contract that was announced in July amid an early-season meltdown on and off the pitch.
Barca revealed last month that the five-time Ballon d'Or winner, 30, had agreed a fresh deal which will see him stay at Camp Nou until 2021.
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A press release on the club's website stated: "The deal will be signed in the coming weeks, when Messi returns to the team for pre-season training."
But after Wednesday night's 2-0 loss at Real Madrid in the Spanish Supercopa - a 5-1 aggregate defeat - Barcelona were forced to defend the fact that Messi is yet to put pen to paper on deal.
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At the unveiling of new €40 million signing Paulinho on Thursday, vice-president Jordi Mestre said: "It is all agreed and we are waiting for a date for the signing. Everything is in place, with just the signature missing.
“Leo's renewal is something we are totally clear about and we have worked on it for a long time. Everything looks very good and I would be very surprised if the signing didn't happen."
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However, Mestre infamously claimed Neymar would "200 per cent" be staying at Camp Nou this summer, which proved to be emphatically wrong when Paris Saint-Germain bid his €222m release clause earlier in August.
Messi's previous deal, which is still valid until the new contract is signed, expires at the end of 2017-18 and the Argentine has a release clause of €250m.