A true fullback.
During his first three seasons, Johnson played in the fullback-less offense of former coach Bruce Arians, who didn't shy away from his dislike of the position. Johnson has only seven career NFL carries with two running backs on the field, according to ESPN Stats & Information. But that will change under offensive coordinator Mike McCoy, who was hired by new coach Steve Wilks in January.
McCoy's new offense includes a fullback. And Johnson, who ran behind a fullback in college at Northern Iowa, is glad to see it.
"Fullback is an extension of him," new running backs coach Kirby Wilson said. "He's almost a bodyguard."
Johnson already has the running thing down. He rushed for 1,239 yards and 16 touchdowns during his last full season in 2016, which ended with a knee injury early in Week 17. Any extra help from a fullback could increase those numbers.
Wilson, who said he's coached a fullback at all 13 previous stops in his career, including his first stint with the Cardinals from 2004 to 2006, said a good fullback -- not just any fullback -- can change the offense and aid Johnson.
"What that means is when a good fullback takes the field, the tempo, the physicality picks up," Wilson said. "As a runner, you have to know how to use a person like that. David's had that some in his past, obviously in college. ... A fullback brings violence to the game, he brings mayhem, he brings destruction, and those are the things that makes a defense a little bit soft over time, if you got a good one. And David will learn to use that type of person again as the system evolves and we get into minicamp, training camp, preseason, etc., and then regular season. I think it'll be a good thing for him."
As Arizona takes a week off before its third set of OTAs, Johnson has yet to experience the "violence" of having a lead blocker since contact isn't allowed during these offseason sessions. Come the third day of training camp, though, when teams are allowed to start wearing pads, Johnson will begin to see the benefit of having a fullback in the NFL, Wilson said.
The decision to add a fullback wasn't made to help Johnson. It was a byproduct of McCoy's system, but Johnson thinks it'll help, and he likes what he sees from Cardinals fullbacks Derrick Coleman and Eli Penny. "They're going to be good."
"I think it makes my job a little bit easier having those guys being able to pick up linebackers or D-ends or anybody on the defensive side," Johnson said. "[It] makes my read a little bit easier."
Wilson called the fullback a running back's "eyes to your running lanes, on your reads, on your decisions and your ball placement." He doesn't think a fullback will change Johnson's style of running. He already describes Johnson as a "spectacular, physical runner," and the two are working on improving Johnson's fundamentals, including eye placement and reading the defense. But Wilson does believe a good fullback could affect Johnson's role in the passing game. In 2016, Johnson caught 80 passes for 879 yards and four touchdowns -- the most that season for a running back by 263 yards. In theory, Johnson's receiving numbers could increase.
"It's all about play-action," Wilson said. "When you have a good fullback, that changes the demeanor of the entire football game and how people will attack the run and the play-action and those deep, deep throws develop through that."
So how do running backs do in McCoy's system? When McCoy took over the Denver Broncos' offense as coordinator in 2009, he inherited a unit that spread around its carries and was led in rushing by Peyton Hillis -- a fullback -- with 343 yards. In McCoy's first year, Denver drafted Knowshon Moreno, who ran for 947 yards. Moreno followed that by leading the Broncos in rushing in 2010 with 779 yards. In 2011, Willis McGahee signed with the Broncos and had 1,199 yards on 249 carries, a year after rushing for just 380 yards on 100 carries with the Baltimore Ravens. When McCoy rejoined the Broncos in 2017 after four seasons as the Chargers' head coach, C.J. Anderson went from 437 yards in 2016 after missing nine games with a knee injury to 1,007 in 2017.
Johnson could see the same influx of yards that running backs in previous McCoy-guided schemes had -- partly because of a fullback.
Wilson isn't convinced a fullback can protect Johnson from getting injured again, though. Johnson has gotten hurt in the most recent two games he played -- a knee injury in Week 17 of 2016 and a fractured wrist in Week 1 of 2017. Wilson doesn't think a lead blocker will decrease the number of hits Johnson will take.
"Fullback has nothing to do with how many hits he takes or not take," Wilson said. "It's those 11 men on defense that determine how many hits he takes. Those guys -- they're paid. They're trying to kill the guy who's carrying the mail.
"Health is all about luck in this profession. It's a game of attrition. Nobody controls that health part. It's just something that hopefully the man above will shine down on him, on our organization and bless all of these young men with some health this season."
Wilks sees things differently, however. He thinks the fullback will help protect Johnson -- and his health -- because he'll be the first line of defense for those defenders swarming Johnson.
"I think it's always a plus when you got somebody to [be] able to take the brunt of the punishment or the blow first," Wilks said. "And, seriously, no, I think he's going to benefit. I think it's important that we have that balance in our offense in the things that we're trying to do."