Seattle coach Pete Carroll said Friday that Browner and Avril will be game-time decisions.
Browner suffered a hamstring injury earlier this week, while Avril is trying to come back from a hamstring injury suffered during training camp.
Carroll said both would have to be worked out before Sunday's game. If Browner can't go, Carroll said Walter Thurmond and Byron Maxwell will play cornerback. Should Avril have to sit, the Seahawks plan to start O'Brien Schofield.
Seattle got good news on its defensive line as both tackles Brandon Mebane (groin) and Tony McDaniel (groin) are expected to play after making it through a week of practice.