The Bears collected several shiny new weapons in free agency and the draft to surround Mitchell Trubisky. But not everyone helping the young quarterback grow catches passes or throws blocks.

First-year offensive coordinator Mark Helfrich and returning quarterbacks coach Dave Ragone both figure to be instrumental in Trubisky's development.

Helfrich operated some of the most explosive offenses in college football history at Oregon, first as offensive coordinator (2009-12) and later as head coach (2013-16). In 2014, Helfrich helped quarterback Marcus Mariota become the school's first Heisman Trophy winner.

"He's a people person and he also has a sense of humor, which not everybody knows," coach Matt Nagy said of Helfrich. "He's great with the guys in there, and he's a teacher. When he's in there, being able to teach concepts and the whys, he does a great job with that, and then he keeps it light. He's a teacher with the players, and the coaches, they respect that."

Ragone, a star quarterback at Louisville who was selected by the Texans in the third round of the 2003 draft, worked closely with Trubisky last season when the second pick in the draft set Bears rookie passing records with 196 completions and 2,193 yards.

"It's nice because they are quarterback guys that really understand the position," Nagy said. "They have a history with it, whether playing it or coaching it.

"We talk football all the time, so I'm able to be out there and oversee it, but [there's] the trust factor of just knowing what these quarterbacks are getting. And then you have [backups] Chase [Daniel] and Tyler [Bray] back there with Mitch. It's a unity between all of them. For us to have that is really comforting."

Nagy, of course, is also known for his work with quarterbacks. Last season as Chiefs offensive coordinator, he helped veteran Alex Smith lead the NFL with a career-high 104.7 passer rating, throwing for 4,042 yards with 26 touchdowns and just five interceptions.

Another Bears assistant is also helping Trubisky, albeit in a much more indirect manner.

"Coach [Vic] Fangio and his guys are doing a good job of mixing different coverages and disguising different looks," Nagy said of the veteran defensive coordinator. "For Mitchell to be able to see those looks on tape, he's building his own library right now within this offense."

With Trubisky and the Bears having completed six of 10 OTA practices as of Thursday, Nagy no longer has to show the offense how the Chiefs ran the system when he was on Andy Reid's staff the past five seasons.

"We don't have to watch Kansas City's offense anymore," Nagy said. "We're building our library now and he's able to see how it works against our defense right now and try not to make those mistakes and make the correct adjustments."

Nagy is happy the Bears have reached that point, but he knows they have miles to go.

"It's nice to be able to see your guys doing it," Nagy said. "They understand that in Kansas City it took us five years to get to that point that we got to. That did not happen overnight. That develops in time.

"We're kind of at a pace right now where we have to at times pull back and say to yourself we're months into this thing, not years. The more reps we get in practice—whether it's a walkthrough, splits, alignments, shifts, motions—the more they can see themselves doing it, that's what we want."