Not quite sure if either of them would be keepers...but I'd probably drop the Wizard.
Malkin, Neal, Richards, Benn, Hossa, Elias, Semin?
Karlsson, Pietrangelo, Kronwall?
To me those could potentially be your 12 keepers. But in any case Lupul has less competition for quality ice time compared to Whitney on a very top six heavy Dallas team.
My two cents.