Lionel Messi's shock announcement that he wants to leave Barcelona looks like the opening salvo in negotiations around the fine detail of his contract.
It will come down to the all-important get-out clause in his contract, says a Spanish sports lawyer.
The 33-year-old Argentine has declared his wish to leave the club whose academy he joined at the age of 13, when he began a glittering career which has soured over the past 12 months under the management of president Josep Maria Bartomeu.
Messi's lawyers have referred to a clause in the four-year contract he signed in 2017 which would have allowed him to leave the club for free, but only if he requested it by June 10.
They will argue that that date - nominally the end of the season - is now irrelevant after the coronavirus delays that led to the season's extension and the team playing deep into August.
The club will argue the May date is the relevant one and so his departure now would trigger a monster ($A1.1 billion) release payment from any interested club.
"I think Barcelona is in a stronger position but Messi has certainly showed the weakness Barcelona might have," sports and business lawyer Santiago Nebot, who has acted as general counsel for Spanish soccer players' union AFE, told Reuters.
"If he says to Barcelona I want to go, give me a free transfer and Barcelona says no, there is absolutely nothing he can do," said Nebot, who has not seen Messi's contract and based his assessment on media reports.
"He is showing this weapon, saying I want to leave if you don't sit down and negotiate, I will try to use this clause, saying that it extends over time and that you could interpret it as being applicable now.
"Because of COVID, what they need to assess as well as the date is the intention of the parties," he added.
"Why June 10? Because June 10 is 10 days after the last match or because it is 20 days before the transfer window opens on July 1?"
Earlier on Wednesday, Barcelona's technical secretary Ramon Planes said "our idea at the club is still to build a new winning cycle around the best player in the world ... we are working internally to convince Leo".