With injuries taking their toll on Seattle's offensive line depth, the Seahawks added guard Landon Turner on Tuesday. Demetrius Knox, an undrafted rookie guard out of Ohio State, was placed on injured reserve, the result of an injury sustained in Sunday's preseason game.

Turner, 26, went undrafted out of North Carolina in 2016 and was signed by New Orleans, where he split time between the practice squad and active roster over the past three seasons, appearing in seven games as a rookie, starting one.

Turner, who is 6-foot-4, 325 pounds, also spent time on the practice squads in Minnesota and Carolina last season, and was signed to a future contract by the Panthers following the season. Carolina waived Turner in May.

Turner provides depth for a line that has battled injuries of late. The Seahawks played Sunday's preseason game minus Mike Iupati, the projected starter at left guard who has been out since early in camp with foot and calf injuries, as well as their top two backup tackles, George Fant, who sprained his ankle in the preseason opener, and Jamarco Jones, though the latter did return to practice late last week. Knox was carted off late in the game with a quadriceps injury that Seahawks coach Pete Carroll called “a nasty injury."