The Bills have been hit hard by injuries this summer and were already going to start the season without running back Karlos Williams among others.
Things got worse Tuesday with word that starting defensive tackle Marcell Dareus is facing a four-game suspension for violating the NFL's substance abuse policy. ESPN was the first to report the possible suspension, and NFL Media confirmed the news.
Williams was also suspended the first four games of the season for violating the league's substance abuse policy.
MORE: Preseason Power Rankings
Dareus had to sit out the season opener last year for his first violation of the policy.