The Bills released DL Lionel Dotson on Wednesday and signed undrafted free-agent DE Sean Ferguson.
Last season, Dotson played in five games for Buffalo and recorded two tackles. He played a combined seven games for the Dolphins from 2008-10.
Ferguson tried out with the Bills during rookie minicamp in May. He had 101 career tackles at Mississippi State.
The team also placed TE Mike Caussin on the active/physically-unable-to-perform list.