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.