The Dolphins signed QB J.P. Losman and placed QB Sage Rosenfels on the reserve/non-football illness list.
Rosenfels was signed as the team's backup quarterback after Chad Henne landed on injured reserve. He was active but did not play in two games with Miami.
Losman was one of five quarterbacks to try out with the Dolphins earlier this month. He last threw a pass in 2009 with the Raiders. Losman spent five seasons with the Bills. He started every game in 2006, throwing 19 touchdowns and 14 interceptions.
Rosenfels released the following statement, according to PFW correspondent and South Florida Sun-Sentinel writer Omar Kelly: "After practicing for a few weeks, especially in the heat, some new indications made it obvious that I need to rest and allow my body to regain all requisite strength."
Losman will back up Dolphins starter Matt Moore, who was sacked four times on Sunday and reportedly suffered bruised ribs.