Tests on Sam Bradford's injured left knee did not reveal any structural damage, and the Vikings now believe the quarterback's status will be week to week, a source told ESPN's Adam Schefter.
Bradford, seeking a second opinion, met on Friday with orthopedic specialist Dr. James Andrews, who performed ACL repairs in 2013 and 2014 on the same knee, which has troubled Bradford since last week and caused him to miss Friday's practice, team and league sources told ESPN's Chris Mortensen. On Friday, Vikings coach Mike Zimmer ruled Bradford out for Sunday's game against the Buccaneers.
Bradford reported Friday morning to the team's medical personnel that he was feeling fairly pronounced pain in his knee, a day after there was optimism expressed by Zimmer that the quarterback was feeling better and had a chance of playing against Tampa Bay. Bradford also sat out the Vikings' Week 2 loss to the Pittsburgh Steelers.
The Vikings will again look to Case Keenum as their starting quarterback on Sunday. Keenum struggled against the Steelers last week, going 20-of-37 for 167 yards.
Earlier this week, Bradford described the injury as a noncontact one suffered during the Vikings' Week 1 win over the New Orleans Saints.
Bradford severely sprained his left ankle in 2011 and missed six games for the St. Louis Rams. The ACL tear in 2013 limited him to seven games, and the tear in 2014 kept him out for the entire season. He had a concussion and a sprained left shoulder that cost him two games with the Philadelphia Eagles in 2015.
This is the 10th year out of the past 13 in which the Vikings have had to start more than one quarterback, with Brett Favre (2009), Christian Ponder (2012) and Teddy Bridgewater (2015) the only ones who made it through an entire campaign unscathed. In only seven of the 35 years since the 1982 strike, the Vikings have had the luxury of sticking with one quarterback, with Warren Moon (1995) and Daunte Culpepper (2000, 2002 and 2004) also on the list.
By all accounts, Bridgewater is progressing and could be ready to be taken off the PUP list after Week 6. However, the Vikings have an incentive to keep him on there all season, which would give them added flexibility next season.
Thanks to an obscure CBA rule, any player left on the PUP list all season would have his contract "toll," or carry over, to the next season. So even though Bridgewater is now in the last year of his contract -- and Minnesota declined to pick up his fifth-year option -- the Vikings would have him for another year under the terms of this year's contract if he remained on the PUP list all season.
ESPN's Courtney Cronin and The Associated Press contributed to this report.