‘”Without a doubt, I’m letting guys down,” Boyes said here Friday on the eve of the Sabres’ game against his former team, the red-hot St. Louis Blues. “You’re here for a reason. Everybody has a role to play. I’m no exception. I look at myself. I’m real disappointed with the way things are going. But whatever happens in the past is past. I have to figure out real quick how to help out.”‘