Buffalo Bills defensive end Mario Williams was playing with a torn ligament in his wrist that made it like he was playing with one arm, according to a team source.

It explains why Williams had surgery during Buffalo's bye week that ordinarily would sideline players more than one game.

But because Sunday's game was against his former team, the Houston Texans, Williams was more determined than ever to play. Williams had a sack and five tackles Sunday in his first game at Reliant Stadium since signing a six-year, $100 million contract with the Bills (3-5) in the offseason, but the Texans came away with a 21-9 victory.

Those who know Williams insist this situation is similar to the toe injury he battled his rookie season, not telling many about it. Once he underwent toe surgery, Williams' play improved dramatically and he became a huge factor.

The feeling is that Williams' bye-week wrist surgery will have the same effect.

Information from The Associated Press was used in this report.