Vikings quarterback Sam Bradford is out for Sunday's game against the Tampa Bay Buccaneers, head coach Mike Zimmer confirmed.

The quarterback, who has been limited in practice the first two days of the week because of the left knee issues that kept him out of Sunday's game in Pittsburgh, wasn't taking part in the brief portion of Friday's practice open to the media.

He continues to deal with a knee injury sustained in the season opener against the Saints.

He'll be replaced in the starting lineup by Case Keenum.