The 53-year-old Argentine believes there are few who can match the "lethal" Bianconeri ace - but acknowledges that a Ballon d'Or win is unlikely
Vidal has established himself as a vital part of Antonio Conte's side since his move to Turin in 2011 and has already scored 16 goals in all competitions this season as the Bianconeri bid for a third successive Serie A title.
The Chile international described himself as the world's best midfielder last month and his national team coach believes the 26-year-old sets the standard in his position in much the same way as Messi does for attackers across the world.
"There's only one Messi. He's unique. But we can say that Vidal is the Messi of midfielders," Sampaoli told Tuttosport.
"There are few like him: he is flexible, lethal, an expert in stealing the ball."
Sampaoli acknowledged that Vidal faces an uphill battle to emulate Messi in Ballon d'Or successes, however, as Fifa's top individual prize is more often awarded to forwards.
"The Ballon d'Or is difficult. It's generally awarded to attackers, to goalscorers," he admitted.
Sampaoli, who has been watching several of his Chile stars in action across Europe in recent weeks, also suggested Juve boss Antonio Conte could create the ideal attacking set-up if he should make a move for Barcelona's Alexis Sanchez.
"Alexis Sanchez would be perfect for Conte. Him, [Fernando] Llorente, [Carlos] Tevez: a potential attack like few others in the world," mused Sampaoli.
Finally, the 53-year-old conceded that Mauricio Isla's World Cup spot could potentially be under threat due to his lack of playing time at Juve this season, but insists he still considers him an important part of his side's set-up.
"Any player wants to play as much as possible. He knows that he runs the risk of losing the World Cup," added Sampaoli.
"He is equipped with tactical intelligence and quality. But for me, nothing changes. He remains essential, even though he is fighting for his place at Juventus."