The team is adding defensive lineman Sylvester Williams to the 53-man roster from the practice squad in a corresponding move.
The Broncos signed Bortles on Sept. 24 after starter Drew Lock's shoulder was injured. Bortles served as the backup behind both Jeff Driskel (432 passing yards, three touchdowns, two interceptions, 54.7 completion percentage) and Brett Rypien (295 passing yards, two touchdowns, four interceptions, 67.5 completion percentage).
"[Lock] is trending the right way," head coach Vic Fangio told reporters Friday.
As for what would determine whether Lock starts, Fangio said "just a conversation with him about where he's at, that's basically it."
And so Bortles is without a team yet again. The 28-year-old spent his first five seasons with the Jacksonville Jaguars after being selected third in the 2014 draft, largely serving as the starter. But issues with consistency and accuracy (59.3 career completion percentage) largely plagued his time there.
His best season came in 2015, when he threw for career highs in yards (4,428) and touchdowns (35) but also interceptions (18). And the Jags went to the postseason just once (2017) during his tenure.