ST. LOUIS — The St. Louis Rams have agreed to a contract with Brady Quinn, quickly adding another quarterback after losing Sam Bradford to a season-ending left knee injury. Kellen Clemens, the backup the past two years, will make his first start since 2011 on Monday night against the Seahawks. Quinn was a first-round pick by the Browns in 2007. He has bounced around and was cut by the Jets on Monday. Bradford injured his knee in the fourth quarter Sunday in a loss at Carolina and is expected to undergo surgery in a few weeks when swelling subsides.