The winger has been impressive playing the inside role for Spurs.
Kulusevski is happy to play wide right, but has been used more centrally to great effect.
Postecoglou told reporters: “Deki is doing great. He's been out of this world in many respects as to what he's able to do in a central role. We used him wide last year because we didn't have too many options out there and that's where he was comfortable in.
“We started using him inside and I felt he felt that it unshackled him a little bit. He has an unbelievable capacity to run on and off the ball, his physical numbers are ridiculous and he has the quality to hurt teams with that.
“At times out wide he might've felt suppressed, especially in our system where you have to hold your position and not be involved, he's a player who wants to be involved. We brought a couple of wide players in this year and I thought let's go with him inside.
“We played with him as a nine in pre-season and he made an impact. The beauty of Deki is he's just getting started, he enjoys the role, he brings a different dimension to us because there's not many players like him.”