According to a report in Madrid daily El Mundo, the contract Messi signed last November includes a clause that he must remain a Barcelona player only as long as the club is playing in "a top-level European league."
A source at Barcelona told AFP that "for reasons of confidentiality the club never comments on contractual relations with players."
Catalonian nationalists proclaimed independence from Spain after a referendum on October 1, precipitating a crisis which is still unresolved.
The Spanish civil and football authorities have said repeatedly that Catalan secession would end the participation of the region's clubs in the Spanish League.
If Catalonia becomes independent and Barcelona are booted out of La Liga and cannot persuade another major league (France, Italy, Germany or England) to give them a home, Messi could leave without having to pay his 700 million euro ($843 million) buyout clause, said El Mundo.
The newspaper said that leaving La Liga would have the same impact on the rest of the Barcelona squad, whether they have specific clauses or not, because it would represent a substantial change to the circumstances under which they signed their contracts.