It was the only trophy that had eluded Messi throughout his illustrious career and it was secured in the most nerve-shredding way imaginable, as Argentina beat France on penalties after a chaotic 3-3 draw after extra time.
Messi scored two goals and also took Argentina’s first penalty in the shootout in Sunday’s final.
Guardiola coached Messi at Barcelona from 2008 to 2012 – a team widely considered the greatest of all time – winning a remarkable three La Liga titles and two Champions Leagues in that four-year spell.
“Everyone has [an] opinion, but nobody can doubt that he’s there with the greatest of all time,” Guardiola told reporters ahead of Thursday’s Carabao Cup match between City and Liverpool.
“For me, I’ve said many times, he’s the best. It’s difficult to understand that a player can appear and compete what he has done in the last 50 or 70 years.
“The people who saw Pele, for example, or [Alfredo] Di Stefano or [Diego] Maradona … they can say they’re my favorite because often these opinions are sentimental.
“But, on the other side, if he [Messi] wouldn’t have won the World Cup, the opinion of what he has done for the world of football, in my opinion, of how he is as a player wouldn’t have changed absolutely anything,” Guardiola added.
“For him, it is the final cherry on an incredible career.”