PHOENIX – Matt Patricia’s philosophy when it comes to running backs is simple: You need at least two of them to succeed.

That was the case before Kerryon Johnson missed six games with a season-ending knee injury last year, and that will be the case going forward even with Johnson expected to be fully healthy for the start of offseason workouts next month.

Patricia said Tuesday at the NFL’s annual meeting that he has no plans to baby Johnson in his return to the field but that the second-year running back’s workload could be limited by more natural factors.

“Regardless of Kerryon, I think it’s a position-specific thing where those guys, they take a lot of hits,” Patricia said. “They’re in those situations a lot where their bodies are taking some pounding so you want to be conscious of how many plays they’re getting, especially early on in the year. And obviously, we just want to win. That’s the most important thing. But you do have to look at big picture and say, ‘OK, great, we could win a couple now, but if we wear this guy out and he doesn’t help us in the long run then what’s the trade off?’”

A second-round pick out of Auburn, Johnson averaged 15 touches per game as a rookie despite starting the season as a backup to LeGarrette Blount.

Johnson’s workload increased as the season went on — he had three of his four highest-carry games after the Lions’ Week 6 bye, including in a Week 11 win over the Carolina Panthers when he got hurt — and he’ll enter this fall as the team’s unquestioned No. 1 running back.

“The thing about it, and it’s no different from any player going from Year 1 to Year 2, it’ll be a whole different set of circumstances for him next year,” Patricia said. “Teams will definitely identify him differently. Teams are going to come at him differently. They’re going to put more pressure on him. So is the passing game, is the run game, is the blitz-pickup game going to look the same? We don’t know. But what I do know is, he loves the game, he works extremely hard. This guy wants to win. He cares. So I know he’s going to get better, we just got to see how he responds to the different looks that he gets from the other coaches.”

While Johnson should see an uptick in carries under new offensive coordinator Darrell Bevell, the Lions still have room to add a complement to him the backfield.

The Lions lost out on running back Malcolm Brown when the Los Angeles Rams decided to match their two-year restricted free agent offer — general manager Bob Quinn said Brown is the type of young (25), versatile (he’s a solid special-teams player), relatively inexpensive back the Lions want to add to their roster — but they also re-signed Zach Zenner and return Theo Riddick on the final year of his contract.

Zenner and Riddick's presence won’t prevent the Lions from adding another back in next month’s draft or in the second wave of free agency, where Spencer Ware, Javorius Allen or Rod Smith could be options.

But Patricia said he’s “excited” to see how Zenner returns from a strong finish to 2018, when he was the team’s best running back after Johnson went down with his injury.

Zenner finished third on the Lions with 265 yards rushing last season and closed the year with a career-best 21-carry, 93-yard performance in a win over the Green Bay Packers.

“Whatever he makes his role is what his role is going to be,” Patricia said. “I’m excited to see that. He’s coming off a year with a lot of confidence. I think it was really great for him to have the end of the year he did where it was a situation where sometimes it takes a little bit of the light bulb to go one and a little bit of confidence and you see players step into this new role of ability and he’s certainly one of those guys we’re excited about.”

Contact Dave Birkett at dbirkett@freepress.com. Follow him on Twitter @davebirkett.Read more on the Detroit Lions and sign up for our Lions newsletter.