If Walker get called up and produce at least 1 point I'm shocked. What I have saw about him isn't what qualify as NHL forward. Yes its very short sample, but its just what my eyes saw.
To me if Walker gets called up its just bigger paycheck for himn which is just fine, but I highly doubt he'll success. He isn't excatly that speedy such a small player. I just saw at pre-season games he got pretty easily man handled, and looked he doesn't belong in this league, in other hand Kostin was performing another level and producing at pre-season in better linemates compare to AHL. His size and skill set worked well at NHL level.
I agree not to rush Kostin in to NHL, but short time at NHL would give him extra boost and confidence what needs to improve and spirit which has been his so called 'thing' when he has speaken go to back Russia.
I understand thinking process you award players who has been good at AHL, but I don't see him improve team who is already +25 years old.