It’s why he needed this move. You might argue he was playing against superior technical players at U21 when playing U21 Spain or U21 Portugal but Kilmarnock players will be a lot more physical than 18 year old U21’s and a lot more experienced and street wise.
I always thought last season his issue was physical. He couldn’t deal with playing back to goal, accelerating in tight space or simple shoulder barges. He looked like a boy, a very talent boy but in a men’s league.
Constantly playing against men and doing lots of gym work to improve core strength is the key. His brain and technique has always looked excellent and that is the more important if you want to be elite but he needs to get to premier league physical level which he isn’t yet.