Zeman has spent most of his career at the helm of Italian club sides and he still follows Serie A with close interest.
The coach is currently unemployed after his spell at Red Star and he has returned to speak of all things Calcio.
The former Lazio man is full of praise for Mourinho and he believes the coach is one of the best in the world. "I really like Mourinho because he has the courage to always say what he wants," Zeman told La Gazzetta Dello Sport.
"People are not used to hearing someone like him here in Italy. Mourinho has won so much and he has shown he is one of the best."
However, the Czech - Italian coach believes the 'Special One' needs to prove his worth at San Siro and that Amantino Mancini and Ricardo Quaresma were not the right signings.
"He still has not shown his values at the club because the team is still so good from before," added the coach.
"I also believe Quaresma and Mancini are not the right players for Mourinho's style of play, even though he wanted them at all costs."
The Nerazzurri clash with Werder Bremen in the Champions League later tonight and Mourinho will be hoping his side bounce back to stabilise the squad after they were rocked by Milan during the derby.