Johnson was selected by the Cleveland Browns in the 4th round, 120th overall pick of the 2012 NFL Draft.
On May 9, 2012 Johnson signed a 4-year contract with the Browns.
After being injured in the pre-season, Johnson returned to the Browns lineup in week 5 and made his first career start week 6. Johnson finished with a career high, 10 tackles, week 8 against the Chargers. Johnson's season finished with 36 tackles, and two stuffs in 10 games.
On August 31, 2013 Johnson was waived.
On September 1, 2013 Johnson was claimed off waivers by the Kansas City Chiefs.
In Johnson's second season, he recorded 17 tackles, one sack, and one forced fumble while playing all 16 games.
In Johnson's second season with the Chiefs he had his best season of his career. Johnson had 51 tackles and one forced fumble.
On September 5, 2015, Johnson was released by the Chiefs.
On September 6, 2015, Johnson was claimed off waivers by the Tampa Bay Buccaneers. On September 15, he was waived after suffering an injury.
On October 5, 2015, the Jacksonville Jaguars signed Johnson to provide depth at linebacker. The Jaguars released Johnson on October 28, 2015.
Johnson was signed by the Detroit Lions on November 4, 2015. On November 14, 2015, the Lions waived Johnson.
Johnson was signed by the Miami Dolphins on November 17, 2015. On December 1, 2015, he was waived. On December 22, he was re-signed by the Dolphins. On September 3, 2016, he was released as part of final roster cuts.