Injuries have kept him down, and now with Thomas Greiss playing excellent in net in relief of Antti Niemi, it would seem that Niittymaki's days in teal are numbered.
He has two choices: be dealt (to a team hopefully in need of a decent goaltender), or be the man in Worcester.
If you're asking GM Doug Wilson, I would think he would take the latter.
Alex Stalock and Harry Sateri are the go-to guys in net in Worcester, and it would not be right to hold those players back in order to ready Nitty for another run in the NHL.
Thus, there is only one answer, and it is the trade block.
Here are five teams that could use a player like Antero Niittymaki in net.