With plenty of issues up front, the Panthers have added a veteran offensive lineman.
Carolina signed Gabe Jackson to the practice squad, the team announced on Wednesday.
Jackson started 31 games for Seattle over the past two seasons, including 15 last year. But the Seahawks released him in March. He has not been with a team since.
A third-round pick in the 2014 draft, Jackson spent his first seven seasons with the Raiders.
Panthers guards Chandler Zavala and Cade Mays both sustained injuries last week, leaving Carolina with little depth for the interior of their offensive line.
The Panthers will play the Buccaneers on the road in Week 13.