He most likely replaced McKenzie who will go back to the AHL. The worst forward in the NHL is still a better player than generic AHL guy.
You'd think so but I'd say that actually Korpikoski is worse than a generic AHL guy.
He has absolutely no hands, is weak on skates and gets pushed down very easily, cannot even pass let alone receive one and if he ever gets an opportunity to shoot, it definitely isn't going in.
He cannot play well defensively and the only reason he gets called a defensive forward is because he is even worse at offense. His corsi% was the worst on his team last season. And that's on Edmonton Oilers.
He skates fast, that's about it.