On Friday, CBS Sports' Jason La Canfora reported that Johnson and the Cardinals are "not close at this point" and "have a long ways to go to complete a deal."
In mid-August, Johnson said he understood hammering out an extension could be difficult since he missed almost all of last season with a broken wrist.
"I think that's what it is—I didn't play," Johnson told Darren Urban of the team's official website. "I didn't play last year. I was hoping my production from my second year and what I did my first year would help out, but the NFL is what have you done for me lately, so hopefully I can prove it once the season starts."
The 26-year-old is two seasons removed from a breakout 2016 campaign in which he totaled a league-high 2,118 yards and 20 touchdowns from scrimmage.
Now in the final year of his rookie deal, the 2015 third-round pick will try to replicate that sensational season in hopes of inking a contract similar to the $60 million pact Los Angeles Rams running back Todd Gurley signed in July.
The Cardinals open their season Sept. 9 against Washington at University of Phoenix Stadium.