It's strange to see someone other than Martin St-Louis, but we all understand why. Letowski is there for the media, for the players, and during the games, but that doesn't mean he's the one pulling the strings.
Indeed, even though St-Louis has returned home, he's still the one pulling the strings. Letowski is in constant communication with him.
This is significant information. It means that Trevor isn't the one making decisions, but rather executing them. Martin is still the one sending directives, and we love it.