The Atletico Madrid star was expected to join Barca before the World Cup, but chose to stay - which he announced in a controversial pre-World Cup documentary.
Messi reflected: "The theme of the documentary was to explain where he was going. I learned the news during the World Cup, but I did not see the entire documentary.
"Everyone does what is best for him. If he decided to stay, that's his decision.
"We must think about the future and the goals we have set for ourselves this season."