The former second-in-command at Barcelona has said that the Portuguese star may never scale the heights that the Argentine has done due to lacking "something special"
Both stars netted hat-tricks during the week in their club's respective Champions League opener, with the Argentina international taking his European goals total to 62, just nine shy of Raul's all-time record in the competition.
And Ten Cate, whose spell with the Catalans coincided with the emergence of Messi, says that the 26-year-old's Portuguese rival will never reach his standard because he lacks that "something special".
"Messi is unique. There are no other players like him; he is on another level," the 58-year-old told AS. "Neither Cristiano [Ronaldo] or Neymar are close to him because Messi is out of this world.
"Cristiano is also at a very high level, but Leo [Messi] has something special that Ronaldo does not have."
Xavi dropped to the bench in favour of Cesc Fabregas for the 4-0 thrashing of Ajax on Wednesday, but Ten Cate added that coach Gerardo Martino must not make a habit of omitting the veteran midfielder, who orchestrates his team's attack.
"Xavi has to play," he added. "He is the boss; he leads the team's rhythm like an orchestra and he is the director of the play."
The Dutchman, now interim coach at Sparta Rotterdam, worked under Frank Rijkaard with the Catalans and helped guide the club to its second Champions League title in 2006.