Messi, 25, who broke Gerd Muller's record of number of goals scored in a calendar year, is favourite to claim the FIFA Ballon d'Or for the fourth consecutive time. Ronaldinho also expects him to win the award which is contested by Messi's closest rival Cristiano Ronaldo and teammate Andres Iniesta.
But the 2012 World Cup winner said Neymar will be the best in the future.
"Cristiano has been making history for many years now, but Messi is the best in the world, and one day Neymar will be the best," Ronaldinho was quoted by Xinhua.
Neymar, 20, has scored 54 goals in 102 appearances for club Santos while has also netted 17 times in 27 matches for the national team.
Former world player Ronaldinho also praised Messi for scoring 86 goals in 2012.
"For me Messi is the best in the world," he said. "For the last few years he has played at a level of football we have never seen before.
"I'm very proud to speak of him, because I was there when he started off and now he is the best in the world, it makes me so happy," he added.