RENTON, Wash. (AP) — Two youngsters are about to get their chance to prove they can be long-term options to help the Seattle Seahawks’ struggling defense. Linebacker Jordyn Brooks and defensive back Ugo Amadi will step into starting roles beginning Sunday against Dallas following season-ending injuries to Marquise Blair and Bruce Irvin. Amadi will be the nickel cornerback while Brooks’ role is still unknown. Seattle coach Pete Carroll says Brooks will start against the Cowboys but declined to say at which position.