Brock Osweiler was built to play in Broncos’ coach Gary Kubiak’s system. The 6-foot-8, 240-pound stout, yet mobile, quarterback has been patiently waiting on the bench behind Peyton Manning, and is scheduled to make his first career start Sunday at Chicago.

Osweiler’s chance also is likely an opportunity to see Kubiak’s offense as the Broncos’ head coach intended to run it.

The play action pass is the staple of the offense, except Denver hasn’t had much success with it all season. The blame is multi-faceted. Play-action plays thrive when there is a threat of a running game or the quarterback taking off.

Denver hasn’t had either.

Enter Osweiler, whose mobility might add a threat opposing defenses haven’t faced much this season.

“You see Brock yesterday. He moved around, made some great plays, made some guys miss,” Kubiak said Monday. “Every player has their abilities and their strengths, but we’ve got to run our scheme better regardless.”

Osweiler’s best skills, a strong arm, quick feet and elusiveness, could fit Kubiak’s designs well.

Kubiak had a quarterback of a similar stature in Baltimore last season with 6-6 Joe Flacco, who was coming off his worst season, 19 touchdowns and 22 interceptions in 2013. Kubiak arrived as offensive coordinator, and under his tutelage Flacco had career highs in passing yards and touchdowns.

Osweiler, getting ready to make his first NFL start, has a long way to go to match the veteran Flacco, but he fits the mold of the quarterback Kubiak likes to run his offense, one with a big arm and mobility.

The last time Osweiler stepped on the field as a starter, he threw a 78-yard pass to Andre Caldwell down the seam for a touchdown in the Broncos’ preseason finale against Arizona. That’s the sort of big play the Broncos have been missing this season.

Kubiak said for this week, and however long it takes for Manning to heal, his message to Osweiler was that the Broncos “are all yours.”

“You practice new things and then you discuss what you like about it, what you don’t like about it and just move forward from there,” Osweiler said.

Look for Kubiak to use Osweiler on bootleg plays, something Manning struggled to run.

“There’s some things a mobile guy can do that a guy that can continually stand in the pocket can’t, ” tight end Vernon Davis said.

Cameron Wolfe: 303-954-1891, cwolfe@denverpost.com or @CameronWolfe