The N.F.L. has ordered a six-game suspension against Tyrel Dodson, a Buffalo Bills rookie linebacker, who faces misdemeanor charges of domestic violence and disorderly conduct related to an incident involving his girlfriend at a nightclub in Scottsdale, Ariz., in May.

An N.F.L. investigation determined that Dodson had violated the league’s personal conduct policy, the Bills announced Thursday. Dodson spent the off-season practicing with the team before being placed on the commissioner’s exempt list on Aug. 31, when the Bills made final cuts to establish their regular-season roster.

The exempt list allows players to be paid but not to be with their teams on game days.

Dodson was an undrafted rookie free agent out of Texas A&M, and he signed with Buffalo on May 9.