Lee and Nissley spent the 2013 season on injured reserve.
The 23-year-old Lee signed with the Falcons last May after going undrafted out of Alabama State. He reportedly suffered a leg injury in training camp.
Nissley, 25, also spent the 2012 season on injured reserve. According to the Atlanta Journal-Constitution, Nissley suffered two ACL tears in his time with the Falcons. A UCF product, Nissley signed with Atlanta in April 2012.