The 34-year-old forward returned to his boyhood club Santos in January 2025 and played a key role in their survival in the Brazilian top flight, scoring five times in their last five matches.
But Neymar, who has struggled with injuries in recent seasons, remains doubtful for participation at the World Cup this year.
"I don't know what will happen from now on, I don't know about next year," he told Brazilian online channel Caze on Friday.
"It may be that when December comes, I'll want to retire. I'm living year to year now."
"This year is a very important year, not only for Santos, but also for the Brazilian national team, as it's a World Cup year, and for me too," Neymar said.
Neymar, who recently underwent successful knee surgery, has scored 79 goals for Brazil, the highest by any player, but he has not featured for the national side since October 2023.
Brazil manager Carlo Ancelotti has made it clear over the past year that he will only include players who are fully fit for the World Cup, scheduled to take place from June 11th to July 19th in Canada, Mexico, and the United States.