Riley (knee) will undergo surgery this week to repair a torn meniscus, Vaughn McClure of ESPN.com reports.
Riley, a third-round pick out of LSU, had started five of the Falcons' first six games of the season at weak-side linebacker before suffering the knee injury in Sunday's loss to the Patriots. The Falcons likely won't issue a timetable for Riley's return until after the surgery is completed, but his specific procedure typically requires four weeks of recovery. In order to address Riley's absence, the Falcons signed veteran Sean Weatherspoon to bolster their depth at the second level.
