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.
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.
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."
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.