ORCHARD PARK, N.Y. (AP) -- The NFL has suspended Bills running back Karlos Williams the first four games of the season for a drug offense.

Bills officials announced the suspension Friday but did not specify how Williams violated the league's substance abuse policy.

Williams had a breakout rookie season in 2015, complementing LeSean McCoy. Williams had nine combined touchdowns rushing and receiving and averaged 5.6 yards per attempt.

The league said in a statement that Williams will be able to return after the Bills play the Patriots Oct. 2.

Bills officials say they're disappointed in Williams and will work to help him ''in making better decisions moving forward.''

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