The writing has been on the wall for months, and at least one report already exists to this end, but nobody has yet stated it as plainly as John Wawrow of The Associated Press with this headline: Bills planning to cut Mario Williams in offseason.
In the likely event that this plays out, and the Buffalo Bills do end up cutting Williams after the season, then this Sunday's season finale against the New York Jets will be his final appearance in a Bills uniform.
In his four seasons with the Bills, Williams has accumulated 42 sacks, two Pro Bowl appearances, and earned a first team All-Pro nod just last season, when he set a career high with 14.5 sacks. That gives you an idea of just how quickly things can change; Williams has publicly questioned his coaches all season while racking up just four sacks in a disappointing year for the defense.
In the same report, Wawrow relays that veteran defensive tackle Kyle Williams - presuming he recovers in full from a knee injury that landed him on IR - remains in the team's plans, and won't be released despite an $8 million salary cap number. That pales in comparison to Mario Williams' $19.9 million number, as does the cap savings if released ($5 million for Kyle, compared to $12.9 million for Mario).