ENGLEWOOD, Colo. -- During John Elway's tenure as the Denver Broncos' top football decision-maker, the team hasn't always seen its first-round selections pan out the way it had hoped. Linebacker Von Miller, the first-round pick in 2011, is the only former Broncos draft pick on the current roster who has been named to the Pro Bowl while with the team.

Two of the last seven first-rounders -- Sylvester Williams (2014) and Paxton Lynch (2-16) -- are no longer on the roster and the Broncos did not engage the fifth-year option on linebacker Shane Ray's deal this season.

This year's first-round pick, linebacker Bradley Chubb, is the biggest, and fastest, reason why Ray's playing time has been greatly reduced. And Chubb, if he continues on his current career arc, just might have a Pro Bowl in his future according to Miller.

Chubb leads all NFL rookies with 6.5 sacks, which is also tied for the fourth-highest total in the league overall.

"Chubb is like he's been doing this for a long time, his approach and how he goes about it," Miller said. "If he can keep going, we'll get our rush going, make those game-changing plays we want on defense.”

But the 3-4 Broncos need more than just Chubb.

The Broncos have their toughest road test of the season on Sunday when they go to Arrowhead Stadium to face the 6-1 Kansas City Chiefs, who lead the league in scoring and whose quarterback, Patrick Mahomes, leads the league in touchdown passes.

Cornerback Chris Harris Jr. called it "a potential season-changing game" for the Broncos.

In short, the Broncos need all hands on the proverbial deck.

And they really need another strong performance from two former first-round picks: Tackle Garett Bolles (first round 2017) and cornerback Bradley Roby (first round 2014). The pair have struggled at times this season, but each had their best outing of 2018 in the Broncos' 45-10 victory over the Arizona Cardinals last week.

Bolles wasn't penalized for the first time since the opener and the Broncos largely kept quarterback Case Keenum out of harm's way. Roby finished the evening with his first interception of the season and played aggressively. Just three games ago against the New York Jets, Roby suffered his worst game as a pro as three New York touchdowns could be traced to him.

"I just want to win," Roby said. "I don't feel like I'm worried about mistakes or whatever, but I do want to make more plays and perform like I know I can. When we ball as a defense, I want to be helping make that happen."

Said Harris: "Ro, he's just got to keep playing. Just keep lining up, keep playing."

Before the Broncos' win over the Cardinals Bolles and Roby looked to be wobbling.

"[Bolles] is getting coached, he's working and I think he's getting better all the time," said Broncos coach Vance Joseph. "I've said he's fighting for his life out there, he's going against the best pass-rushers in football every week. He's getting better, he's working."

Bolles has struggled with penalties -- he has six holding penalties this season and was flagged a team leading 15 times as a rookie last season. The Broncos have put offensive line coach Chris Strausser on the sideline during games to try to help Bolles through the rough spots in real time.

"We all know what we need to do," Bolles said. " … I always believe in my team and my coaches. I think everybody should be ready because we're coming."