Lock, according to multiple team sources, was vaccinated and tested positive for COVID-19 on Sunday morning after he had tested negative Saturday before the team left for Texas. The Broncos determined his close contact was someone away from the Broncos' complex.
The Broncos went through the contact-tracing protocols Sunday morning with players, coaches and staff members who were around Lock. Teddy Bridgewater started in the Broncos' dominant 30-16 win, with Brett Rypien serving as the backup.
Broncos coach Vic Fangio, while clearly concerned, kept it all together as kickoff approached.
"I've gotten really good, things that I have no control over, I don't sweat," Fangio said.
After the win, Bridgewater said he was tested and was waiting for results, when he was informed there was an error. As a result, he wasn't cleared until a "few minutes" before he took the field for warm-ups.
"I didn't have to get swabbed again," Bridgewater said. "They just had to run the test again."
Lock was the second Broncos player this week, and third in the past two weeks, to be ruled out due to COVID-19 protocols. Tight end Noah Fant tested positive Tuesday and is on the reserve/COVID-19 list, and guard Netane Muti is on the reserve/COVID-19 list after testing positive in late October.
This is the second time Lock has had to miss a game because of COVID-19 protocols.
In Week 12 of the 2020 season, Broncos backup Jeff Driskel tested positive for COVID-19 and the rest of the team's quarterbacks were all deemed close contacts, making Denver's entire QB depth chart unavailable for a game against the New Orleans Saints.
Running back Phillip Lindsay opened the game at quarterback in the Wildcat formation, as wide receiver Kendall Hinton, a former quarterback at Wake Forest, played 24 snaps at quarterback with 24 hours' notice in a 31-3 Broncos loss.
Lock and the other quarterbacks were later fined by the team for violating COVID-19 protocols, including meeting together without masks and not using their contact-tracing devices properly.