If we're going to be talking about defensemen that haven't started the season off great, there's 2 that really stand out, Rielly and Muzzin. I'm not sure why everyone keeps raving about Rielly, he has the tools but not the iq, he's constantly getting beat on the defensive side of the game as well. It's one thing to look like a fool against McDavid but when Connor Brown is beating you on the outside, it's an issue. Offensively, he just doesn't know what to do, he has the speed, can't really decide when to pass and on the powerplay he's absolutely useless.
As for Muzzin, he looks slow and sloppy this year. I'm not sure if it's the weight he put on but he seems to be a step behind everyone. While Bogosian isn't the quickest, he atleast realizes that and doesn't put himself into position to get caught where as Muzzin has been and isn't quick enough to recover