Brandon Allen, who was claimed off waivers from the Los Angeles Rams on Sept. 1, will start Sunday's game against the Cleveland Browns. Rookie Brett Rypien is being promoted from the practice squad to serve as Allen's backup.
Schefter reported Thursday that surgery was not expected to be required for the bulging disc in the veteran signal-caller's neck.
As John Elway looked for stability at the quarterback position last offseason, Denver acquired the Super Bowl XLVII MVP from the Baltimore Ravens in March in exchange for a 2019 fourth-round pick.
Flacco completed 65.3 percent of his passes for 1,822 yards, six touchdowns and five interceptions in eight games in his first season in Denver. He posted a 2-6 record, though four of the losses were decided by a single possession.
After a 15-13 loss to the Indianapolis Colts on Sunday, he voiced his frustration with the coaching staff's approach to the game:
Flacco had rarely missed a game in his career up until last year. The 2008 first-round pick started the first 122 regular-season contests, as he did not miss a contest until Week 12 of his eighth season. He missed just six games through his first decade in the league, with all six coming in 2015.
He had started the first nine games of 2018 before a hip injury forced him out of action. That injury wound up costing him his job, and ultimately led to the end of his time in Baltimore, as rookie Lamar Jackson went 5-2 down the stretch while leading the Ravens to the postseason.
While Flacco has thrown his last pass in 2019, it remains to be seen what his future in Denver will be. The 34-year-old has two years and $44.5 million remaining on his contract beyond this season.
The Broncos used a second-round pick on former Missouri Tigers quarterback Drew Lock, who has spent the entire season on injured reserve due to a thumb injury, in April.