Barcelona board spokesman Josep Vives said he has no evidence that Lionel Messi is interested in leaving the club.
He reiterated his plea for fan support after the Argentina player appealed against a 21-month prison sentence for tax fraud imposed by a Catalan court.
Barcelona over the weekend launched a campaign urging fans to "express their sympathy" after Messi and his father, Jorge, were found guilty by a Barcelona court of three counts of defrauding the tax department.
Messi's management company said the pair would take appeals to the supreme court, even though neither man is likely to serve any time in prison.
"We have maintained contact with his entourage and we are not aware Leo wants to leave the club, we simply don't get that feeling," Vives told reporters on Monday. "We are not worried about this, nothing has reached us to suggest this is the case."
Vives encouraged fans to show their support for Messi via social media.
"Messi is being treated unfairly and the club are putting themselves in a position to defend him. We have a clear conscience and will not back down. We are inviting supporters to join our campaign," he said.
Vives: "Invitamos a la gente que se apunte a la campaña de apoyo.Es fácil: una foto, un gesto y #TodosSomosLeoMessi" pic.twitter.com/Ku6DJkzXYd
- FC Barcelona (@FCBarcelona_es) July 11, 2016
"It is a simple campaign, but we hope that it will show how much we support him," Vives said. "We are talking about Messi, a player who was 19 when he signed all those contracts and it has been proven that he had no knowledge of all their details. He just focused on football and signed the contracts he was told to sign by his advisers."
Vives accused the state prosecutors of putting together a campaign against Messi to try to discredit him.
"The club cannot tolerate this," he said. "There are other well known personalities who have not been subject to this type of situation as Messi has been. This shows lack of respect and we don't want that for any fan, for any socio and neither for Messi. That is why we are putting this campaign of support together."