The former Brazil international believes the Argentina skipper still has work to do in order to be considered the best player in the history of the game
The 1994 World Cup winner says he considers Pele, himself and Diego Armando Maradona to be the best players in history, in that order.
Meanwhile, Messi claimed earlier this month that he could not judge whether Pele was a better player than him as he had never seen the former Santos forward play, to which the 70-year-old replied by saying he would send the Argentine a copy of his movie.
And Romario feels that the current Barcelona star would only gain by watching the documentary.
"If Messi sees the video, he'll probably learn some things," Romario said at a press conference.
"You simply cannot compare him with Pele. You cannot say he is the same when he has never won a World Cup.
"Messi has all the conditions to be the best one day, but first he has to overcome Maradona, Romario and then eventually Pele."
Romario wore the Barcelona jersey from 1993 until 1995 and won one La Liga title with the Catalans.