BUFFALO, N.Y. (WIVB) — Two hours before kickoff in their second preseason game, the Buffalo Bills announced they have released second-year running back Karlos Williams.

The move comes as a surprise after Williams rushed for 517 yards on 5.6 yards per carry in his rookie season. He scored seven touchdowns and served as a more than capable backup to starter LeSean McCoy. Many viewed Williams to be a draft steal, since the Bills had selected him in the 5th round of the 2015 NFL Draft.

Williams didn’t help himself this offseason. He showed up to minicamp out of shape. ESPN reports his weight ballooned to 261 pounds, when he was listed at 229. Williams also earned a four-game suspension for a violation of the NFL’s substance abuse policy.

Williams posted a message on his Instagram account in response to his release.

“I will never forget my first carry in #TheRalph,” Williams wrote. “I wanna thank the #billsorganization for the opportunity of a life time. #FirstNflCarryFirstNflTouchdown #BillsMafia”

The Bills now turn to Reggie Bush, Mike Gilislee and rookie Jonathan Williams to help in the backfield.