I just watched CSKA vs Jokerit and have mixed feelings on Mamin. Just like in the season opener, he played with an Eeyore energy that I can't see an NHL coach accepting. He was gliding around making alibi plays on defense and then had the occasional burst of speed up the ice when the play turned, which immediately seemed to exhaust him and he would head for the bench.
That said, he also played like a poor man's Jagr. He had plenty of defensive zone exits where he would calmly make a constructive play, creating time and space for himself and his linemates. On offense he would also create time and space with his big body, long reach, and puck control. And he found good positions on offense, getting a couple of open shots and a breakaway. In total I counted four shots and they were all quality chances. Unfortunately the shots were really weak, as if he was just happy getting the shot away rather than trying to score. I don't think he was on the ice for any of the goals in either direction.
It's fun to see him on an actual scoring line in Moscow. He certainly seems to fit best there. Considering how well Barkov and Huberdeau played with an aging Jagr, it would be awesome if Mamin could step in there as another big body with soft hands. These two games I've seen makes me doubt that he can actually be productive enough against NHL opponents though.