The Barcelona star has endured a mixed relationship with Argentina's support throughout his international career, with the fact he left home for Catalonia aged 13 sometimes used to argue he lacks true commitment to the cause.
"The other day I was talking to a friend and he was saying, 'Look, if you had stayed with Spain, you would be world champion,'" Messi explained to El Trece, having watched his Barca academy colleagues Andres Iniesta, Xavi and Gerard Pique lead a glorious era for La Roja.
"But it would not have been the same. Obviously, it never crossed my mind."
Messi suffered final heartbreak with Argentina in three consecutive years as Germany's extra-time win in the 2014 World Cup showpiece was followed by penalty shoot-out reverses against Chile at the Copa America in 2015 and 2016.
Gonzalo Higuain was made a scapegoat for those losses in some quarters following a string of high-profile misses, but Messi reported the Juventus striker is in high spirits ahead of Russia 2018.
"He is very relaxed, aware of what is coming, he is very involved," he added.
"He said a great truth - it is a new opportunity, more than a rematch.
"This group had too many criticisms. We reached three finals, but we received a lot of criticism. We became stronger than ever."