Rapoport noted that Keenum is guaranteed $7 million in 2019, which means he may be asked to take a "massive" pay cut if Denver is unable to trade him.
Finding a trade partner to take Keenum would be far more attractive to the Broncos than releasing him since he would count for $10 million in dead money against the salary cap.
Last offseason, the Broncos signed Keenum to a two-year, $36 million contract in free agency. The 30-year-old veteran went 6-10 as the team's starter and put up fairly mediocre numbers in comparison to what he did the previous year.
Keenum completed 62.3 percent of his passes for 3,890 yards, 18 touchdowns and 15 interceptions last season.
That came on the heels of a career year with the Minnesota Vikings in 2017. In 15 appearances and 14 starts, Keenum went 11-3, completed 67.6 percent of his passes and threw for 3,547 yards, 22 touchdowns and seven interceptions.
Keenum also took Minnesota all the way to the NFC Championship Game.
Per Heath Cummings of CBS Sports, Keenum and Flacco have had nearly identical numbers since Keenum entered the NFL in 2012, despite Flacco being the bigger name due to his one Super Bowl win in Baltimore:
While Keenum has just one highly productive NFL season to his credit, there may be a market for his services.
The fact that he is signed for just one more season means any team that acquires him won't have to make a significant commitment. Also, the Broncos are unlikely to ask for much in return given his struggles last season and because they need to clear some salary to make room for Flacco.
If Denver does trade Keenum, it would open up room to possibly select a quarterback such as Dwayne Haskins or Kyler Murray with the No. 10 overall pick in the 2019 NFL draft and allow them to learn under Flacco next season.