Brown (knee) has undergone season-ending surgery, Brady Henderson of ESPN.com reports.
Brown suffered the injury in Sunday's loss to the Cardinals. The fourth-round rookie had come on as a significant contributor in the Seahawks' secondary over the previous four weeks. In his absence, Sidney Jones will likely step back into a larger role. Brown is expected to remain on crutches for six weeks before beginning a 6-to-7 month rehab program.