Mikko Rantanen could be on the move again if Carolina cannot sign him to an extension. Brock Nelson, Erik Karlsson and brothers Brayden and Luke Schenn are all in the mix. Seth Jones, Ryan Lindgren and Gustav Nyquist have already changed teams.

Mikko Rantanen could be on the move again if Carolina cannot sign him to an extension. Brock Nelson, Erik Karlsson and brothers Brayden and Luke Schenn are all in the mix. Seth Jones, Ryan Lindgren

Which defensemen can actually move the needle? Which defensemen can capably fill depth roles? Which defensemen should teams probably avoid?

Seth Jones, Ryan Lindgren and Gustav Nyquist have already changed teams, and there is still plenty of time for more to happen. Even after a series of deals prior to the 4 Nations Face-Off, this week should bring plenty of action before the NHL trade deadline Friday.

Here are the obstacles to trading Karlsson: • He has a no-movement clause. Though many assume he would be willing to move on if asked, he still has the power here. The team hasn’t played well during his time in Pittsburgh, but he seems to genuinely like playing for the Penguins.

Martin Necas Jonathan Drouin — Casey Mittelstadt — Valeri Nichushkin Ross Colton — Jack Drury — Joel Kiviranta These are not the Penguins of 10 years ago - or even five - though some of the names remain the same.

Brock Nelson, Erik Karlsson and brothers Brayden and Luke Schenn are all in the mix. Seth Jones, Ryan Lindgren and Gustav Nyquist have already changed teams. And there is still plenty of time ...