Career
He was signed by the Indianapolis Colts as an undrafted free agent in 2006. He played college football at Southern Mississippi Johnson played high school football for Coach Jerry Alexander at Moss Point High School in Moss Point, Mississippi.
He was a late starter who began playing as a junior, lettering two-years.
He was also invited to play in the MHSAA All-Star Game following his senior year. Indianapolis Colts
After going undrafted in the 2005 NFL Draft, Johnson signed with the Indianapolis Colts on May 5, 2006.
Johnson was released at the end of training camp on September 2, 2006. He was re-signed on January 4, 2007, and assigned to the Cologne Centurions.
Philadelphia Soul
Johnson signed with the Philadelphia Soul in 2008.
Calgary Stampeders
On February 19, 2009, Johnson was signed by the Calgary Stampeders. New Orleans Saints
On January 20, 2011, Johnson was signed to a three-year contract with the New Orleans Saints, a deal that with his signing bonus could be worth up to $1.8 million, said his agent Bardia Ghahremani. Minnesota Vikings
On March 19, 2014, Johnson signed a one-year contract worth $845,000 with the Minnesota Vikings.
Johnson ended his 2014 season with 22 combined tackles, one forced fumble and a career high of 6.5 sacks.
He re-signed with the Vikings on a three-year contract worth $7 million on March 8, 2015.
