He told Genting Casino: "You don't really care about the 100 million price tag when someone does that well.
"I looked at it last year, and I said that he would do the job of both Xhaka and Partey and that's what he's done.
"He's given Arsenal the balance in the midfield that allows them to release two players in front of Declan Rice.
"He allows other players to go out and play. Martin Odegaard has a new lease of life with Rice in the team.
"Havertz has come alive and he's fitted into Arsenal's style one minute he's floating about, coming deep, the next he's scoring headers and acting as a target man, but Rice allows Arsenal to get more out of him too.
"Declan lets other players express themselves. He's that good. I called it last summer.
"I knew he would be a fantastic signing for Arsenal, and I think he has transformed Arsenal from a good team into an awesome one.
"Hopefully he will move on to one of Real Madrid and Barcelona because he's too good for Arsenal."