The forward has scored 58 goals in all competitions for Barcelona so far this term and Del Piero feels the 27-year-old is the best in the world.
"Messi is the number one. He has talent, instinct, passion and magic," Del Piero told the official Barcelona website.
"Messi is part of football heritage and we’re so lucky that he’s living in our time and that we can enjoy watching him."
The ex-Italy international was equally effusive in his praise of Andrea Pirlo and Xavi, hailing the intelligence of the veteran midfielders.
"We’re talking about the Olympus of football, on the greatest level of intelligence.
"They are two unique parts of football history, real phenomena. It has been a pleasure to play with and against them."
Del Piero also had his say on Juventus boss Massimiliano Allegri Barcelona's Luis Enrique, as the two coaches prepare their side for Saturday's final in Berlin.
"Allegri took over a winning team and improved it without shaking things up too much. He did it gradually, by inserting his principles without losing confidence in his team. Juve play serene, organised football now. They play good football, it’s very technical.
"As for Luis Enrique, he’s also done an extraordinary job. The team has found brilliance and unity, with the guarantee of three great players up front who have complete freedom of expression, yet they always work for the good of the team."