By Chris Emma–

CHICAGO (CBS) — Rookie reserve quarterback Mitchell Trubisky looked to be everything the Bears hoped in his preseason debut Thursday evening, while Mike Glennon struggled in his first action as the new starting quarterback.

Moving forward, that structure will remain the same.

Coach John Fox has no intentions to open a quarterback competition after a 24-17 loss to the Broncos at Soldier Field, one in which the future face of the franchise Trubisky outclassed the starter Glennon.

“Our depth chart is not going to change after one game — and particularly a preseason game,” Fox said about a potential quarterback battle. “Our first unit went against probably one of the top three defenses in the league. I think you have to look at a lot of different things. I can understand how (the media) might think, but we’re not going to change a whole lot after one game.”

Glennon’s start wasn’t pretty. He played four series, finishing 2-of-8 for 20 yards and an interception, which was a pick-six on the opening drive. Glennon threw the ball into triple coverage, where Broncos cornerback Chris Harris Jr. was waiting and returned it the other way for a score.

Glennon was replaced by backup Mark Sanchez in the second quarterback, as the Bears had initially planned. Sanchez went 1-of-4 for just four yards, a strike to tight end Daniel Brown.

Then came Trubisky, the No. 2 overall pick, who finished 18-of-25 for 166 yards and a touchdown. He took over with 1:55 remaining in the first half, with the Bears interested to see how he would react in a two-minute drill scenario. Trubisky led the Bears on a six-play, 50-yard drive, going 4-of-4 and capping it with a two-yard strike to veteran receiver Victor Cruz.

Trubisky would complete his first 10 passes before an incompletion on an overthrow to Cruz, which led to the receiver getting shaken up on the play. His other major mistake came on a third-down play in the third quarter, when the play clock expired and brought a delay-of-game penalty at the two-yard line. The Bears would be backed up five yards and had to settle for a field goal.

Overall, Trubisky’s debut went exactly as the Bears could’ve hoped, but even he knows there’s no quarterback competition — at least for now.

“Mike’s the starter,” Trubisky said. “This is his team.”

Chris Emma covers the Bears, Chicago’s sports scene and more for Follow him on Twitter @CEmma670 and like his Facebook page.

Watch & Listen LIVE