Muzzin was a mess last night, and hasn't been great for a few games now. Still, Greene would be an ideal partner for him once he comes back. We saw what Muzzin can do when he is with a highly competent defender, he just needs that stability backing him up.
Doughty, Voynov, and Muzz/AM all being able to take more chances offensively with a solid partner will really increase our back end scoring. That is what I think we miss most with Greene out, even more than his solid play and penalty killing. Carter allowed everyone to slot into their correct roles when he was acquired, I think we will see a similar effect defensively when Greene comes back.