The influential midfielder has praised his Blaugrana team-mate and feels he does not need international success to go down as the finest player in history
The attacker was unable to guide Argentina past the quarter-finals at the 2006 and 2010 World Cups in Germany and South Africa, respectively, and he has often been criticised for his performances for the Albiceleste.
Nevertheless, Xavi has insisted that his Blaugrana team-mate will be remembered as the greatest of all time - if he does not win a major trophy at international level.
"Leo doesn't need to win the World Cup to be considered the best player ever," the Spain international told The Sun.
"I say that for those who demand he wins the World Cup to be considered the greatest ever in history.
"He's decisive in every game he's played in for six or seven years."
The 26-year-old Messi has been in fine form in recent weeks after initially struggling to live up to the high expectations following his return from injury.
Messi has netted 13 goals in 17 La Liga appearances this term, scoring five in his last three games.