Steelers add veteran cornerback Sean Murphy-Bunting, place Derrick Harmon on injured reserve; sign Marte Mapu to practice squad
The Pittsburgh Steelers signed cornerback Sean Murphy-Bunting to the 53-man roster from the Tampa Bay Buccaneers’ practice squad, placed defensive lineman Derrick Harmon on injured reserve and signed linebacker Marte Mapu to the practice squad, the team announced Monday. In a related move the Steelers waived Doneiko Slaughter from the 53-man roster. Harmon was injured in Thursday’s game against the Cleveland Browns, the team said.
Murphy-Bunting, entering his seventh NFL season, brings significant experience to Pittsburgh’s secondary. He has appeared in 82 career games with 65 starts and has 11 interceptions, 34 passes defensed, eight forced fumbles and two fumble recoveries. He was a second-round pick (39th overall) by Tampa Bay in the 2019 draft and spent his first four seasons with the Buccaneers. He started in Super Bowl LV and finished that game with six tackles and a pass defensed.
He signed with the Tennessee Titans in 2023, starting all 14 games he played. He spent the 2024 season with the Arizona Cardinals, where he started 15 games and had three interceptions. He missed the 2025 season on the Cardinals’ injured reserve and was signed to Tampa Bay’s practice squad to start the 2026 season before the Steelers added him to their active roster.
Marte Mapu was selected by the New England Patriots in the third round (76th overall) of the 2023 draft and has appeared in 44 games with 10 starts. He has 69 tackles, three interceptions, half a sack, five forced fumbles and 20 special teams tackles in his career; in 2025 he played 17 games and had 13 tackles, one interception, a forced fumble and 12 special teams tackles. Mapu was traded to the Houston Texans this past offseason. He played college football at Sacramento State, where he was the highest drafted player in school history, the Big Sky Defensive Player of the Year in 2022 and First Team All-Big Sky.
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NFL Sports Blog Take
Adding Sean Murphy-Bunting provides the Steelers with a veteran corner who has substantial starting experience and playmaking numbers, which should help the secondary after Derrick Harmon was placed on injured reserve. Marte Mapu’s special teams production and defensive snaps history give Pittsburgh a developmental option and immediate depth on special teams. Waiving Doneiko Slaughter and moving Harmon to injured reserve indicate the team is adjusting the roster to address recent injuries and to bolster experienced depth in the defensive backfield.