Miller has not been great this year, but I think he's really been hampered by Trouba's play. I took a look at the 5v5 advanced stats for our D pairings, and most of the Miller-Trouba pair's stats (CF%, FF%, xGF%) look pretty good. It's the GF% that is abysmal.
So what does that mean? Are they being plagued by the bad puck luck we're seeing this year? I dug a bit deeper and looked at the GA/60, SCA/60, and HDCA/60. The GA/60 for Miller-Trouba was pretty bad, and I also want to note that Trouba is involved in 3 of the 5 worst GA/60 pairings this year (Trouba with Miller, Jones, and Fox). The SCA/60 for Miller-Trouba were not significantly worse than the other pairs, but the HDCA/60 were terrible. Among all pairings for the Rangers this season with at least 10 minutes of 5v5 TOI, Trouba is involved in the 3 worst in terms of HDCA/60 (again, Miller-Trouba, Fox-Trouba, and Jones-Trouba). We are bleeding high danger chances against whenever Trouba is on the ice with anyone. Miller's numbers in these same stats are incredibly good with Fox, and reasonably good with Schneider, albeit with fewer minutes.
What are the options if you break up Miller and Trouba? Either you have to put Lindgren with him in the hopes that he can stabilize Trouba, or you put him with Hajek and try to shelter his minutes (although that would mean Schneider moves up to play tougher minutes). I would like to see Miller and Fox get an extended look together as a shutdown pairing.