In his 16 games he had 29 tackles. After the 2006 season his contract expired and he was not re-signed. On April 4, 2007, he signed with the St. Louis Rams as an unrestricted free agent. Walls played in five games and recorded nine tackles. He was waived on October 12, 2007. Walls signed with the Baltimore Ravens on May 20, 2008. He was released at the end of training camp. Walls signed with the Calgary Stampeders on September 22, 2008. His first two weeks with Calgary were spent on the practice roster before being activated and starting against the Saskatchewan Roughriders on October 13. Against the Roughriders he led the Stampeders with nine tackles and recorded his first interception in the CFL. After his debut in Calgary, he started every game for the rest of the year. In all of his starts with the Stampeders he got multiple tackles. He ended up with 23 tackles on the year but missed the playoffs including Calgary's 96th Grey Cup victory with an injury. On May 15, 2009, Walls was traded to the Winnipeg Blue Bombers. After one season in Winnipeg, Walls signed as a free agent with the Eskimos on March 22, 2010. He was released during the following off-season on May 27, 2011.