The Bills announced several roster moves Tuesday, including the previously reported signings of familiar faces Philly Brown and Trae Elston.
They also signed free agent safety Shamarko Thomas.
Injuries to safety Colt Anderson, linebacker Ramon Humber and wide receiver Jordan Matthews prompted the signings. Humber and Matthews both need surgery for thumb injuries, and Anderson will undergo surgery on a broken arm.
Buffalo placed Anderson on injured reserve and released defensive end Eric Lee and safety Robert Blanton.
The Steelers made Thomas a fourth-round pick in 2013. He served mainly in a backup capacity for the Steelers and played mainly on special teams, appearing in 48 games in four seasons.
Thomas, 26, signed with the Jets in the offseason. The Jets released him during final cuts Sept. 2.