croco

I think it can be a mental issue moreso than a positional problem since the 2 and 3 are pretty much interchangeable. If you know you are listed as a forward and your coach is telling you that he wants you to play inside more, you might just do that. Coming in as a rookie it is pretty clear that he was not well coached, otherwise it would have not mattered like you said, although he would have been a small forward anyway.

What it will come down is also who he will be on the floor with, what the spacing will ideally look like and how his role is going to change with a new coach.