The 10-year veteran has "cold-like symptoms" but is expected to fully recover, per ESPN's Adam Schefter.
Mike Klis of 9News reported that Jackson began feeling congested two days ago and experienced chills soon afterward. The positive test result was revealed on Wednesday morning, and he will now enter quarantine for two weeks.
Jackson recently helped lead a June 6 protest in Denver alongside Broncos teammates and coaches to end systemic racism and police brutality following the May 25 killing of George Floyd in Minneapolis Police custody, but his appearance is not to blame for his COVID-19 diagnosis.
"No, the doctor said with the congestion starting two days ago that I picked it up this weekend. It definitely wasn't from the march," he told Klis.
Per Klis, over 50 Broncos and all 25 team coaches were at the protest.
The 32-year-old is one of numerous NFL players and coaches who have tested positive for COVID-19, including teammate and linebacker Von Miller, Dallas Cowboys running back Ezekiel Elliott and New Orleans Saints head coach Sean Payton.
Jackson, who played for Alabama, suited up for the Houston Texans from 2010-18. He joined the Broncos during the 2019 offseason and amassed 71 tackles, 10 passes defended and two interceptions last year. He also scored a defensive touchdown versus his former team in a 38-24 road win.
The Jackson news comes shortly after comments made by NFL chief medical officer Dr. Allen Sills to reporters on Wednesday regarding the league's developing COVID-19 protocols and testing guidelines, per Nick Shook of NFL.com.
As Shook wrote:
"Those guidelines weren't ironclad, though, and Sills said protocols are still being developed, with a very likely chance the testing strategy will look different from start to end of season as science evolves, per NFL Network's Tom Pelissero. The plan as of now is to also test everyone who will be exposed to players and coaches—officials, for example—just prior to gameday.
"The overarching theme of the process is essentially everything remains fluid. The NFLPA and NFL 'are working to figure out how to apply the principals of the recommendations (from a special task force) as it relates to the calendar and schedule,' Sills said, per NFL Network Insider Ian Rapoport."
The league and NFLPA released a nine-page protocol for the 2020 season on June 7 regarding club facility protocol safety guidelines.
As of now, most teams are scheduled to begin training camp on July 28, per Schefter, with a typical four-game preseason slate preceding the regular season, which starts in September.
Numerous coaches are concerned about the current schedule, however, in light of Elliott and other Cowboys and Texans players testing positive for COVID-19, per ESPN's Ed Werder:
The regular-season opener is currently slated to take place between the visiting Houston Texans and host Kansas City Chiefs on Thursday, Sept. 10.