Johnson has been fully cleared after a wrist injury limited him to one game in 2017. There were reports that he might return late in the 2017 season, but it did not happen.
The 26-year-old Johnson told reporters that he's ready to show that he's recovered from his injuries and is ready to work with Sam Bradford, who takes over at quarterback for the retired Carson Palmer.
"I'm very motivated. Not really just about the people out there, it's really about myself and coming back to the team, for my teammates for the coaches," Johnson said. "For everything being so new. It's about being able to bounce back and play the sport."
Having a healthy Johnson available is critical for the Cardinals and new coach Steve Wilks, who said he plans to rely heavily on the run game.
Johnson was a first-team All-Pro in 2016, when he rushed for 1,239 yards and 16 touchdowns. He also caught 80 passes for 879 yards and four scores while starting all 16 regular-season games.
The Cardinals ranked 22nd in the league in total offense last season and were 25th in scoring, averaging 18.4 points per game.