SANTA CLARA, Calif. – The Panthers have placed centers Ryan Kalil (shoulder) and Gino Gradkowski (knee) on injured reserve.
Kalil, a five-time Pro Bowler and four-time captain, left the Week 11 victory over the Saints and did not make the West Coast trip for last Sunday's game at Oakland and this Sunday's game at Seattle.
Gradkowski, Kalil's veteran backup, had been battling through a knee injury and was forced to leave Sunday's loss to the Raiders. Tyler Larsen took over at center when Gradkowski went down. With two open spots on the active roster, the Panthers signed center Ryan Wendell and offensive tackle Dan France, who could be needed this week against the Seahawks after starting right tackle Daryl Williams suffered an ankle injury versus Oakland. Right guard Trai Turner moved to right tackle - a position he last played in high school - and versatile lineman Chris Scott filled Turner's spot.
Head coach Ron Rivera praised how everyone played in their new roles, but it's a challenging set of circumstances, a reality offensive coordinator Mike Shula made special note of at a meeting Monday.
"When we started our offensive meeting, I had guys raise their hands who played positions that they hadn't played before. We had a few guys up front doing it," Shula said. "We're going to look at different combinations."
Wendell is a seven-year veteran who has experience at center and guard. He last played for Patriots in 2015 before being placed on IR. Wendell started at right guard for New England in the Super Bowl XLIX victory over Seattle.
France was an undrafted free agent out of Michigan State in 2014 and spent his entire rookie season on the Bengals practice squad. He split time on the Bengals' and Browns' practice squads in 2015. This is his first time on an active roster.
Carolina also filled two open spots on the practice squad by adding two young offensive tackles – Tyrus Thompson and Jake Rodgers.
Thompson was selected in the sixth round of the 2015 draft by the Vikings. He was at training camp this season with the Saints. Rodgers was selected in the seventh round of the 2015 draft by the Falcons. He was at training camp this season with the Giants.