The Denver Broncos searching for a quarterback to take control dates to Peyton Manning's retirement in 2016.

Brock Osweiler was the heir apparent but bolted for Houston, and the next few years were littered with options who failed to permanently win the job.

The Chargers erased that issue as Justin Herbert has not only secured the No. 1 job in Los Angeles, he is quickly emerging as one of the better quarterbacks in the NFL. He's coming off a career game in a win over Pittsburgh last Sunday and now faces a stout pass defense when the Chargers visit Denver on Sunday.

Herbert had 382 passing yards and three touchdowns and rushed for 90 more in the 41-37 win over the Steelers. Things might be tougher against the Broncos, who boast the ninth-best passing defense in the NFL entering Week 12.

Denver's defense gets a boost if linebacker Bradley Chubb can play. He had surgery on his left ankle after the second game of the season and returned to practice this week.

"I thought he looked good, and he felt good," coach Vic Fangio said. "Hopefully [he'll] do a little bit more (Wednesday) and then see where he's at."

Denver (5-5) could be without left tackle Garrett Bolles for a third straight game. He missed the last two with an ankle injury but tested positive for the coronavirus coming out the bye week. He needs two negative tests before Sunday to be able to play.

The Broncos activated guard Austin Schlottmann for the COVID-19/reserve list and signed guard Zack Johnson to the practice squad.

Sunday's game will also be the first time Fangio will coach against his former assistant Brandon Staley. Fangio was the defensive coordinator for the Chicago Bears when he hired Staley to be his outside linebackers coach in 2017. They were together for three seasons, with the last with Denver in 2019.

Staley became the defensive coordinator for the Los Angeles Rams in 2020 before the Chargers hired him to be their head coach entering this season.

Fangio knew Staley was head coaching material, he just didn't expect it to happen so quickly.

"When I interviewed him, I knew he had the good ability to be a really good coach, but for me to predict he would be a head coach four years later, I didn't predict that," Fangio said.

Staley has led Los Angeles (6-4) into playoff contention in his first year behind Herbert and a strong offense. Defensively there will be challenges Sunday due to key injuries.

Cornerback Asante Samuel Jr. is in the concussion protocol after suffering the injury on Sunday. Defensive tackle Linval Joseph is in COVID-19 protocol and won't play Sunday, nor will defensive back Mark Webb Jr. due to a knee injury.

Defensive linemen Jerry Tillery and Christian Covington tested positive for COVID-19 last week but are likely to be activated before Sunday's game.

"We're taking it case by case, just making sure," Staley said. "Both of those guys are feeling fine right now, but when they get back to doing football just want to be aware of their overall conditioning and be able to assess that. How much they play or don't play will be predicated on their endurance."