WESTFIELD, Ind. – Bears rookie Roschon Johnson plays running back with a linebacker's mentality.

"I'm a guy who likes to use his body as a weapon and kind of play off of that," Johnson said Wednesday night after the first of two joint practices with the Colts. "That's definitely a tool in my toolbox that I try to use every day."

Johnson's physicality was evident in last Saturday's preseason-opening win over the Titans when he rushed for a team-high 44 yards on 12 carries, with a long run of 24 yards. It's also been a constant in padded practices throughout training camp. 

"He's physical," said tight end Cole Kmet. "Sometimes I like to just watch other positions' [individual] or 1-on-1 drills and I was watching his pass pro stuff and he'll put his helmet in there. That's cool to see. You definitely gain some respect for those rookies that put their facemask in there and are willing to hit some guys, especially … he's going against D-ends and linebackers who are hitting pretty hard."

Johnson was a power back at Texas, where the fourth-round draft pick played in 47 games over four seasons, rushing for 2,190 yards and 23 touchdowns on 392 carries and catching 56 passes for 420 yards and one TD. Last year he ran for 554 yards and five TDs on 93 carries and had 14 receptions for 128 yards and one TD.

An All-American quarterback at Port Neches-Groves High School in Texas, Johnson was converted to running back as a college freshman and remained at Texas despite the presence of star running back Bijan Robinson, who was selected with the eighth pick in the first round of the draft by the Falcons.

Johnson learned his pass protection techniques at Texas from coaches Tashard Choice and Stan Drayton, who served as Bears running backs coach in 2015-16. 

"They either coached or played in the league, so they kind of knew what to expect, knew how to coach us based off of that," Johnson said. "I took the things that I learned from them and translated them over here to the league."

Pass protection techniques are the same in college and the NFL.

"It's fundamentally the same thing," Johnson said, "it's just you're going against different athletes and a different caliber of player. It's different in that aspect, but ultimately the technique and the fundamentals that I learned at Texas definitely translate here."

Johnson's toughness and versatility have earned him some first-team reps in recent practices—including Wednesday against the Colts. But his mentality hasn't changed. 

"It means a lot, but at the end of the day, regardless of what string I'm taking my reps with, I try to approach it the same way," Johnson said. "It's a blessing, but also I've got to take care of business." 

To that end, Johnson is his harshest critic—something that was evident when he was asked to assess his performance in the preseason opener. 

"It's hard for me; I critique a lot of things," he said. "There were a couple runs that I had I felt like I could have hit smoother, a couple of routes that I felt I could have been more sharp on. Special teams, a couple of assignments that I felt I could have executed a little better, really all across the board." 

As he prepares for Saturday night's preseason game in Indianapolis and ultimately his first NFL season, Johnson remains focused solely on the task ahead of him.

"I'm not trying to aim or look big picture," he said. "I'm just taking it a day at a time. Literally just get better every single day. Whatever I didn't do great on the film that day, I'm trying to correct and get better at. At the end of that time, I'll look up and I'll see what I did."