Deco reckons two-time Ballon d'Or winner Messi is as good an entertainer as Ronaldinho as well as a lethal finisher like Romario and Ronaldo.
All three Brazilian legends played for the Catalans during their careers, as did Deco who won two La Liga titles and one UEFA Champions League crown in a four year spell at the Nou Camp.
"Without being a typical striker who always plays close to the opponents' goal, he [Messi] has already become one of the best strikers in the club's history," Deco told Don Balon.
"He is as spectacular as Ronaldinho and as clinical as Ronaldo and Romario.
"He has everything in one. He scores plenty of goals, but also directs play like a No. 10. He is on track to become the best player ever because of his efficiency and his technical skills."
Messi actually started his Barcelona career on the right wing, but it was only when he moved into a more central and forward role did Barca begin to reap the full benefits of his ability. Pep Guardiola's side won La Liga and the European Cup last season with Messi again leading the team's goal scoring charts.
"Barcelona are a great team," Deco said.
"Not only because they play football of the highest level, but also because they have Messi. It's impossible to say how long they can keep this up, but I think they have two or three more years in them."
However, things are not quite as rosy for the former Barcelona and Chelsea star Deco who is considering hanging up his boots for good after his latest injury ruled him out until September.
It is Deco's seventh major injury since joining Fluminense on a two-year contract from Chelsea in 2010.