ENGLEWOOD, Colo. -- As the Denver Broncos worked their way through the opening days of training camp, cornerback Chris Harris Jr. might have called the shot.

Harris was breaking down one of the Broncos' early practices, and as he prepared to move on to the next thought, he said: "Some of these rookies, those guys are going to play for us."

And while compliments often arrive far too quickly after preseason heroics, consider the Broncos' fingers firmly crossed that the early returns on this year's rookie class mean something when the regular season rolls around. Several members of the Broncos' first-year club made the plays that mattered most in the team's preseason opener Thursday night against the Chicago Bears.

So much so that three rookies helped turn a 17-10 deficit in the fourth quarter into the 24-17 victory.

De'Angelo Henderson was one of the many Denver rookies who impressed the Broncos in their preseason opener. Kamil Krzaczynski.USA TODAY Sports

"We made some plays late in the game; that was fun to see," Broncos coach Vance Joseph said.

First Kyle Sloter, an undrafted rookie who has been the No. 3 quarterback in training camp because rookie Chad Kelly (a seventh-round pick) is recovering from knee and wrist injuries, tossed a 47-yard touchdown pass to rookie wide receiver Isaiah McKenzie with 6:01 remaining to tie the game at 17-17. Then rookie running back De'Angelo Henderson popped through the Bears' front and showed the speed that made him one of the fastest running backs at the scouting combine this past February.

Henderson outran the Bears' reserves for a 41-yard touchdown with 1:49 to play that gave the Broncos the win. Undrafted rookie safety Jamal Carter, who was put into the game early in the first quarter, recovered a fumble and was consistently around the ball in what was one of the most extended looks for any player on the night. Rookie DeMarcus Walker, the Broncos' second-round pick this year, was used at both defensive end and outside linebacker.

And rookie left tackle Garett Bolles, the Broncos' first-round pick in April, started the game.

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There is still plenty of time for things to shake out differently, but it's clear Bolles, McKenzie and Henderson have already grabbed the attention of those who make decisions and will impact the depth chart next month. After Thursday night's game, Joseph referred to both McKenzie and Henderson as "special," while Bolles is expected to be in the starting lineup when the Broncos open the season Sept. 11 against the Los Angeles Chargers.

Joseph had already declared McKenzie the team's top punt returner a week ago, but his work as a slot receiver in practice has quickly put him in the mix on offense. McKenzie can also work out of the backfield as a runner, so his versatility might be an option for offensive coordinator Mike McCoy.

And Henderson is the fastest running back on the roster in an offense that wants to see more big plays from the backfield.

"De'Angelo, very, very fast through the hole, a tough runner, great ball skills in the pass game," Joseph said. "What we saw is what he's been since we drafted the guy in the spring."

Sloter has made the most of his chance to show his potential to be a developmental quarterback. He's flashed some arm strength in camp, and the Broncos like the way he has competed in a variety of situations.

He's likely trying to convince the Broncos to keep him on the practice squad and figures to get his most substantial playing time in the Broncos' fourth preseason game on Aug. 31 against the Arizona Cardinals. Sloter finished Thursday night's game 5-of-6 passing for 94 yards and the touchdown.

Joseph even had to tamp down a little preseason enthusiasm after the game when he was asked whether Sloter had earned a look to be the starter or get some second-team work in practice.

"No, no, we've got Trevor [Siemian], we've got Paxton [Lynch] ... it's Trevor or Paxton's job," Joseph said.