On a night where the defense showed off the quality of its depth by not allowing the Bears to run a play from inside the Denver 40-yard line and the special teams contributed a touchdown via a Bennie Fowler punt block recovered by Zaire Anderson, the offense was inconsistent, driving to just one touchdown while settling for four field-goal attempts, two of which Brandon McManus connected.

For Mark Sanchez, Trevor Siemian and Paxton Lynch, the night was a mixed bag. Each showed promise, but none came out and seized the job.

Sanchez had a 32-yard touchdown pass to Demaryius Thomas that saw him stand in the pocket and absorb a crushing blow as he threw deep up the right sideline. Siemian was accurate on short and intermediate passes, and successfully escaped a heavy pass rush for a 22-yard connection in the final seconds of the first half to set up a field-goal attempt. Finally, in the second half, Lynch went 6-of-7 and would have driven the Broncos into scoring range if not for a spate of penalties.

But each also made mistakes. Sanchez threw an interception as he rolled to the right and tossed the football into triple coverage. Siemian missed on three potential touchdown passes on fade routes up the left sideline. Lynch took three sacks as he tried and failed to escape Chicago's pressure.

"I think as a group we had a good step," Broncos head coach Gary Kubiak said. "I think they went out and played like they've been practicing. We've been pretty solid so we've got to keep moving forward."

But while Thursday's game appeared to be a general step forward, Saturday's practice was a step backward for the quarterbacks -- and the offense as a whole.

Plagued by mental mistakes that included an interception, two other passes that were nearly picked off and a fumbled snap, Sanchez, Siemian and Lynch all struggled.

"We didn't practice very well offensively," Kubiak said. "We're less than 48 hours out of a game and to come back and practice is tough. We handled it defensively, but we didn't handle it offensively. It's disappointing for me."

Sanchez and Siemian split most of the first-team repetitions, with Lynch receiving a handful of snaps with the No. 1 offense, as well.

After Sanchez was intercepted by Lorenzo Doss at the goal line -- marking the fourth consecutive pass in which he was picked off -- Kubiak stopped practice and called the offense together for a huddle. The play was a bit crisper after that, but still wasn't close to what he wanted.

"We'll wake up on Monday and we'll go back to work," Kubiak said. "We'll keep plugging. We are going to find the right one."

But for now, the uncertainty continues.