The Seahawks are keeping the nerve center of their offensive line happy. Center Justin Britt is nearing a three-year extension Thursday with the team, NFL Network Insider Ian Rapoport reported. The pact would be worth more than $9 million per season. A 2014 second-round pick out of Missouri, Britt started 16 games as a rookie at right tackle before bumping down to guard and then center, where he started 15 games a season ago. Offensive line coach Tom Cable gave reporters a window into why Britt was so valuable during an interview two weeks ago.