In light of Russell actually appearing to be a possibility...
Generally in watching him, when opponents enter the zone, he recedes to the hashmarks and just attempts to block shots instead of standing up at his blue line or pushing his opponent towards the perimeter.
On Calgary this past season, one defender (Giordano) who played above 500 minutes 5v5 wasn't a negative Corsi-wise - he was neutral. Nonetheless, Russell still grades out as the second worst possession player on that blue line, behind Wideman. Similarly, for the two seasons prior on Calgary, he was a poor performer despite having relatively neutral zone starts and grading out above only Engelland and Smid.
He was a solid possession guy the three years prior on St. Louis and Columbus - but he also had 36.0/26.4 OZ%/DZ%, so really sheltered minutes.
Russell's 29, so he's in his prime and would be a reasonable bet to maintain his fitness for 3-4 years. If he can get into a system where he's forced to be more aggressive upon zone entry and retaining possession, maybe he'll provide some value. I'm not holding my breath though... stay away.