The stunning suspension of Patriots safety Rodney Harrison by the NFL for admitting that he used a banned substance has repercussions for the team beyond his four-week absence. It calls into question whether other players in the New England locker room are harboring similar secrets. Few would have fingered Harrison, a model teammate and revered team leader, as a culprit before news of his suspension broke last Friday evening. When asked yesterday whether he could be confident that Harrison's use of a banned substance - reportedly human growth hormone - was an isolated incident, Patriots coach Bill Belichick intimated that it was not something he could say with certainty. "I don't have any knowledge," Belichick said before stopping short. "I don't have any more knowledge of it than anybody else does. However, the league monitors and does those things. It's all, it's all outside of the team. We all know what the policies and the procedures are. I don't think there is any need for me to go through them. That's a matter of record."