"We can't hang on what we have done in the Copa America Centenario. There are still many more matches in this qualifying," he said.
"If there is one thing Messi has shown us it is that he makes very good choices," said Argentina coach Edgardo Bauza.
Brazil coach Tite said he was not worried about making any urgent decisions over the captaincy of the Selecao after Neymar stepped down from the job.
Brazil Olympic team stars Neymar, Gabriel Jesus, Gabigol and four others were included on Brazil's World Cup qualifying squad.
Argentina coach Edgardo Bauza says that Lionel Messi made his commitment to his national team clear during their recent conversation.
Lionel Messi has announced his return to Argentina's national team, ending his short-lived retirement from international football.