The running back is slated to be a free agent after the 2018 season, but Keim said the Cardinals won't let him get close to the open market.
"I don't think there is any question David is one of our core players and someone we look forward to having a long-term future with," Keim said, according to Darren Urban of the team's official site.
"(It's) no different from in the past, when we've rewarded players like Patrick Peterson, Chandler Jones, Larry Fitzgerald, and Carson Palmer, just to name a few. There's no doubt in my mind moving forward that we will keep a positive outlook and again, look forward to rewarding him just like we have players in the past."
Johnson missed all but one game of the 2017 campaign due to a wrist injury. Prior to that, he shined during a breakout 2016 season, racking up 2,118 yards from scrimmage and 20 total touchdowns, production that should put him in position to be the highest-paid player among running backs.
Devonta Freeman currently holds that title among backs on long-term deals, earning $8.25 million per season.