He is able to negotiate a pre-contract agreement with clubs outside of Spain and he has been linked with moves to Manchester City, Paris Saint-Germain and the MLS.
In a recent interview with Spanish TV channel La Sexta, Messi revealed he was in no rush to make a decision about his future after attempting to force a move away from Barcelona over the summer.
"Nothing will be crystal clear before the end of the year," he said. "I'll wait until the season is over.
"What matters now is thinking about the team, finishing the year well and not being distracted by other things. I don't know what will happen. I'm focused on what we have here and battling for whatever we can.
"I'm not thinking about how the year will end. As of today, it wouldn't be wise for me to say what I'm going to do because I don't know."
With Messi's future far from certain, former Barcelona striker Samuel Eto'o has claimed that 18-year-old winger Ansu Fati could be "the one to take over".
Speaking to Sport Bible, Eto'o said: "I think he is the one for the future, that said he's presently doing amazing stuff so I think the club really needs to groom him and take very good care of him.
"Let's hope he's the one to take over from Messi."
Former Barcelona midfielder Ivan Rakitic also believes Fati has a bright future ahead of him, telling LiveScore and La Liga: "I think Ansu Fati, who is unfortunately injured at the moment, is the one with the most incredible talent compared to the rest.
"I played with him for a time at Barcelona. He has been unlucky with his current injury, but I hope he can return as soon as possible.
"For me, he is a boy who can be a great player for Spanish football and I am sure that many people, including me, will enjoy Ansu playing at the highest level for a long time."