Also I think Fenton wants to season our goalie prospect in the minors anyway, considering that's what they did with Rinne and later on Saros in Nashville. And for the future, it's better for him to play as much as possible rather than having him as a benchwarmer in the big club.
Now, in the event that Dubs or Stalock gets injured for a few of games, then it might be a good idea to bring him up to test him in one or two games. But if it's long-term injury either one suffers, then I'd say they should bring up Hammond as backup.
The more a goalie plays at that age KK is, the better he becomes.