So, if Bradford is not put on injured reserve, Minnesota would carry four quarterbacks on the 53-man roster.
ESPN reported Bradford had his left knee "cleaned up" Tuesday to hopefully ease his pain.
For weeks, Bradford has battled side effects of a non-contact knee injury he sustained when he led the Vikings to a 29-19 win over the Saints in Week 1.
Not this year: the Vikings placed Sam Bradford on injured reserve after a Tuesday knee scope.
Bridgewater was placed on the PUP list to start the season, and he returned to practice October 18, the first day he was eligible. In 17 games in a Vikings uniform Bradford has 4,259 yards, with 23 touchdowns and five interceptions.
Bradford, acquired in a trade with the Philadelphia Eagles after Bridgewater's injury previous year, has been battling an ailing knee since leading the Vikings to a 29-19 win over the New Orleans Saints in the 2017 opener.
Backup Case Keenum has stepped up as the Vikings starting quarterback, leading the team to three straight victories since their win over the Bears at Soldier Field in Week 5.
The quarterback missed all of the 2016 season after tearing his ACL and dislocating his knee during a non-contact drill in a preseason practice previous year. Bridgewater is scheduled to become a free agent at the end of the season.
Bridgewater, whom the Vikings selected in the first round of the 2015 draft, has not played since the 2015 playoffs.