ALLEN PARK, Mich. — On the first day of the Detroit Lions’ rookie minicamp in early May, running back Kerryon Johnson was excited but anxious, eager to see what the NFL was all about, but unsure of what was to come.

The uncertainty faded quickly, a process that began when new Lions head coach Matt Patricia addressed the team for the first time and started using a phrase that immediately made Johnson feel right at home.

“Be physical,” Johnson recently recalled to Yahoo Sports, with a grin. “And do your job.”

That Patricia would use the latter phrase should be no surprise; it is the one made popular by his mentor, New England Patriots coach Bill Belichick, the man who helped nurture Patricia into one of the league’s top defensive coordinators before he was hired to be the Lions’ new head coach in February.

But in Detroit, the first phrase he uttered — of being physical — has been absent for far too long, especially as it relates to the Lions’ long-inept running game. Since prolific quarterback Matthew Stafford arrived in 2009, only Reggie Bush has topped the 1,000-yard mark. Bush barely got there in 2013, rushing for 1,006 yards.

What’s more, over the past four seasons the Lions’ run game has never finished higher than 28th in the NFL, which has also led the Lions to pass more than they would prefer, even in short-yardage situations.

Players insist Patricia isn’t messing around about improving the run game. When asked how many times Patricia says the word “physical” throughout the course of a day, Johnson briefly pauses to think of the answer before chuckling.

“At least 15 or 20 times — that’s who he is, that’s what he knows,” Johnson said. “And to me, as a running back, that screams ‘run the ball’ in my mind.”

The number hypothesized by Johnson may sound high, but it does not surprise second-year center Graham Glasgow, who also believes that being more physical — and thus, running the ball better — is a major priority this year.

“Yeah, I would say so,” Glasgow said with a laugh. “The word seemingly comes up in every sentence.”

Lions general manager Bob Quinn was blunt about the necessity of this attitude shift after this year’s draft, when he was asked if the 2017 team — which went 9-7 for the second straight season under former coach Jim Caldwell — lacked toughness.

“I think it was lacking,” Quinn said. “NFL games come down to about five plays or less every week, and most of these plays are short-yardage, goal line, third down, red area, special teams. I think when I look back at our team last year, all those critical situations … like it’s goal line, like, we can’t run the ball like half a yard. That bothered me.”

Quinn, who took over as general manager for Martin Mayhew before the 2016 season, has attempted to rectify it by fortifying the running attack, starting with the selection of Arkansas center/guard Frank Ragnow with the 20th overall pick in this year’s draft.

The Lions believe Ragnow, a 6-foot-5, 312-pounder, has the size, strength and quickness to be a high-level interior player. After spending four years in a pro-style, run-heavy scheme in college, Ragnow offers run-game versatility, someone who projects as a plus-plus blocker on the gap-blocking plays preferred by power teams (which tend to be better in short-yardage situations they’ve long struggled with) and as a capable blocker on the zone running plays preferred by teams that lean toward having smaller, more agile linemen.

Ragnow, who will play guard next to 6-foot-7 tackle Taylor Decker (a 2016 first-round pick), theoretically gives the Lions something Stafford has never had — a strong, dependable left side of the line that can overpower on gap concepts and capably execute zone concepts, thus giving the Lions more flexibility to attack defenses.

“Talking about the run game, specifically, you’d like to have a combination of both [zone and gap-blocking],” Patricia said. “It might be a better game to go downhill, or a better game to stretch it and cut it. You have to take a look at both of those options.”

Offensive line coach Jeff Davidson recently added the Lions will attempt to implement as many different run schemes as they can and see what they’re good at. This is often easier said than done, especially since offensive linemen need time and practice to work on their technique and timing, and padded practices are limited in today’s NFL.

Chemistry, however, matters on the offensive line, and the Lions have that in spades, as Ragnow joins a blue-collar bunch that started several games together a year ago. All four of the starting holdovers — Decker, Glasgow and right guard T.J. Lang and right tackle Rick Wagner —have Midwestern origins, something they’ve used to bond with each other.

“I think it’s funny that we can all talk about where we’re from and everybody kind of knows where that is — that part of it is pretty cool,” Glasgow said. “Assignment-wise, technique-wise, all of that is starting to come together, and Frank is picking that up extremely quick. He’s very smart.”

Running behind that starting five will be a deep, varied stable of backs that includes Ameer Abdullah, a nimble former second-round pick who led the Lions with 552 rushing yards last season, not to mention LeGarrette Blount — a 6-foot, 247-pound goal-line banger — and veteran Theo Riddick, an ideal third-down back.

However, it is the 6-foot, 213-pound Johnson who projects to get the lion’s share of the carries down the road, perhaps sooner rather than later. A glider who runs with inside toughness and courage — his NFL.com draft profile compared his style to superstar Le’Veon Bell — it’s not like the Lions selected him in the second round to be a backup for four years.

“In college, we loved being physical, and I come here and get another coach that respects that and wants to push that forward,” Johnson said. “You’ve got to get on board with that, you know?”

Johnson, by the way, is adept at zone running, but is most comfortable running gap plays — a positive sign, considering that’s Decker’s and Ragnow’s primary run-game strength, too.

“If you have really physical o-linemen, they can get a lot of movement at the point of attack,” Johnson said. “Once that happens, it makes my life a whole lot easier.”

There’s that word again — physical. And Patricia has done more than pay lip service to it this preseason. The Lions have been wearing pads more thus far in camp, and Patricia also mandated that all his offensive linemen wear knee braces, to protect their ACLs from the clanging and banging in the trenches.

“It’s not falling on deaf ears,” Glasgow said. “I think it’s gonna become who we are this year.”

More from Yahoo Sports:
• NFL HOF reportedly considering requiring inductees to show up
• Dak Prescott on ‘Get Out’ mural: ‘Everybody has their own opinion’
• Terez Paylor: Tyrod good for Cleveland? Just ask the defense
• Dan Wetzel: How Jim Tressel scandal sheds insight on Urban Meyer situation