The pair are Argentina teammates and Messi knows Barca can buy Martinez this summer for his €111m buyout clause.
“He's spectacular, he's in stunning form. You could always tell he was a great player, but he's really exploded in the last year," Messi told Mundo Deportivo.
“He's good in one-one one situations, fights it out with anyone, wins back the ball, can turn in the box. He's a complete forward.
“He is very similar to (Luis) Suarez, both use their ball to turn, protect the ball, battle and score goals.
“I think all great players will in the end adapt. Luis Suarez has a lot of experience and could help Lautaro settle into the club and the Liga. Of course, this is all a hypothetically speaking..."