The Seattle Seahawks waived/injured DL Ryan Robinson on Monday and signed WR Kasen Williams to a contract, according to the NFL Transactions release.
Robinson, 24, originally signed on with the Raiders as an undrafted free agent out of Oklahoma State back in 2013. He wound up making the final 53-man roster as a rookie, but was later waived at the start of the 2014 season.
Seattle later added him to their practice squad in 2014. They eventually signing him to a future/reserve contract in December of last year, but apparently prefer their other defensive line options.
In 2013, Robinson appeared in 12 games and recorded four tackles and a pass defense for the Raiders. However, he sat out the entire 2014 season.
Williams signed on with the Seahawks back in May as an undrafted free agent out of Washington, so they are clearly familiar with him, despite his limited NFL experience.