Monday's move was expected as Seattle had to add Harvin to the active roster or he would have to remain on the physically unable to perform list for the remainder of the season.
Seattle coach Pete Carroll said Harvin is expected to practice this week, meaning his Seahawks debut could come Sunday against Minnesota. If he's not ready, Harvin could be inactive on game day and his debut could come after the Seahawks' bye week when Seattle hosts New Orleans on Dec. 2.
The Seahawks announced Harvin had returned to practice on Oct. 21.
Seattle released defensive tackle Michael Brooks to clear a roster spot for Harvin.