Messi, 30, is a record five-time Ballon d'Or winner, having enjoyed an incredible career at the La Liga giants.
But the superstar forward, who is preparing for the World Cup in Russia, said he was just like other players.
"I don't consider myself the best, I think I am just another player," Messi told Paper Magazine, in which he posed with a goat for a photoshoot.
"On the field, we are all the same when the game begins."
While he has starred for Barca by claiming nine La Liga titles and four Champions League crowns among numerous other honours, Messi is yet to win a senior trophy with Argentina.
Jorge Sampaoli's men will face Iceland, Croatia and Nigeria in Group D in Russia and while Messi admitted Argentina – runners-up in 2014 – were below the level of the favourites, he hopes they can deliver at the showpiece tournament.
"It will be important to prepare well, because in the qualifiers we were fighting up to the end and we didn't have time to prepare ourselves," he said.
"But we have a good group of players and the Argentine team is always going to be a candidate to win, it doesn't matter how we get there.
"We always aim to win and we will try to go slowly but strongly to advance in the competition."
Messi and Argentina kick off against Iceland on June 16.