From the time he entered the league he had high potential. The most difficult part of playing defense is reading the play, positioning and playing smart with the puck. Sometimes this means just shank it into the corner or off the boards, Reilly struggles at times with the fundamental stuff, some of which is difficult to teach if a player is unwilling to buck his instincts.
Maybe it's a conditioning or a mental block, I don't know. He gets to watch McCabe and Tanev play up close. If he can take 25% more of what they do, it would help his game.
Berube is standing by him. Coaches need to default to that position in general though I do believe public calling out has its place where warranted. I'm not sure Reilly fits that bill...yet... He sees what we all see though and if a team starts struggling, players will feel more pressure to be accountable. Hopefully they have candid discussions in private as with all players of course.
He did say that Reilly doesn't complain about who he plays with and "just wants to win". That's noble and important for a team so in this regard I won't knock him. He also did take a suspension last year when he went after the Sens player for disrespecting the team. In team sports, especially physical ones; this matters.
He must do better though. Clear his mind and be zen with the game.