He said: "What you don't see with Sam is the approach he has with sports science. You don't expect that from him straight away, but you find out when you dig deeper.
"You can also see that he brings in incredible experience of the game. He is very curious about all of these things. He looks for the different percentages to use to help the players.
"It's why he has been so successful with foreign players. Look at the side he had at Bolton with Youri Djorkaeff, Fernando Hierro, Jayjay Okocha and Ivan Campo.
"You have to be something special to understand those cultures and get them to play together. That is the hardest part, making a team out of that.
"I don't think he would have a problem working anywhere in the world and managing a dressing room.
"There are not many dressing rooms that have been so multi-cultural. It is a real skill for a manager to get the best out of players if they have cultural differences and you can understand them.
"Sam has done that in a great manner."