Obomanu was put on injured reserve Tuesday, although no details were given about how severe his injury was, or to which wrist. Seattle also released cornerback Danny Gorrer from the active roster.
To take Obomanu's place, Seattle promoted rookie free agent Jermaine Kearse from the practice squad. Obomanu, a seventh-round pick of Seattle's in 2006, had just four receptions in eight games this season, but was a key contributor on special teams.
The Seahawks also added tackle Michael Person to the active roster from the practice squad and signed wide receiver Phil Bates to the practice squad.