Offensive tackle Levi Brown and tight end David Johnson were placed on injured reserve by the Pittsburgh Steelers on Tuesday.
To fill the roster spots, the Steelers signed free agent tight end Richard Gordon and promoted cornerback Isaiah Green from the practice squad.
Brown (triceps), acquired via a trade with the Arizona Cardinals on October 2, 2013, started Arizona's first four games at left tackle. He did not appear in a game with Pittsburgh.
Johnson (wrist) was in his fifth season with Pittsburgh and had appeared in all five games this season and caught four passes. For his career, Johnson has appeared in 52 games, starting 26, and recording 22 receptions for 216 yards and one touchdown.
Gordon was a sixth-round pick (181st overall) by the Oakland Raiders in the 2011 NFL Draft. He appeared in 27 games for Oakland, starting two, and registering three career receptions, one for a touchdown. The Raiders released Gordon in final roster cuts in August.
Green, a first-year player, was on Pittsburgh's active roster and practice squad since Week 1. He was on the Steelers' 53-man roster during weeks 3 and 4, but was inactive for both games and has not appeared in a regular-season game.