Neither Tatar, nor Nyquist, will ever get traded off this team. Especially not to "give Pulkkinen a bigger role". You can pretty much take that to the bank. You don't trade proven NHL talent and assume the risk on unproven talent if you're in a position of strength (i.e. you're the one with the talent). You make the other team assume the risk. IF one were going to be traded, it would be Pulkkinen. But I doubt any of the three get moved.
I was only saying that I would sign Semin and trade Pulkkinen as part of a package for a higher end d-man, because I think Pulkkinen will only be mediocre in the NHL.