The Bills signed Cain to the practice squad Thursday.
Cain hasn't suited up for NFL regular-season action since 2020 when he played two games with the Steelers, but he's recorded 65 receptions for 787 yards and eight touchdowns in the regular season and postseason across the last two springs with the USFL/UFL's Birmingham Stallions. Now, the 2018 sixth-round pick will compete to carve out a deep depth role with Buffalo.