The Patriots placed safety Dell Pettus on injured reserve, coach Mike Vrabel announced Wednesday.
Pettus, 25, will miss at least four games.
He injured his ankle on a special teams play in the second quarter of Sunday’s win over the Steelers.
Pettus signed with the Patriots as an undrafted free agent in 2024. He has appeared in all 36 games since then as well as Super Bowl LX.
A core special teams player and valuable backup at safety, Pettus has played 471 defensive snaps and 579 on special teams. He has totaled 56 tackles, two sacks and one forced fumble.
The Patriots promoted outside linebacker Jose Ramirez to the 53-player roster in a corresponding move.
Ramirez, 27, has not played since 2024.