Case Keenum's debut in a Broncos jersey will come against the Vikings.
NFL teams announced preseason opponents Wednesday, and the Vikings' opening contest will be in Denver. The date isn't set yet, but will be between Aug. 9-12 in the first week of the exhibition slate.
Keenum signed a two-year, $36 million contract with the Broncos last month as the Vikings pursued and signed Kirk Cousins. The Vikings went 12-4 in Keenum's starts last season, ending in a NFC Championship game loss.
All three former quarterbacks could potentially face the Vikings this season with the Jets (Teddy Bridgewater) and the Cardinals (Sam Bradford) among regular season opponents.
In the preseason, the Vikings will return to U.S. Bank Stadium Aug. 16-19 to host the Jacksonville Jaguars and the Seattle Seahawks the weekend of Aug. 23-26. The Vikings' preseason schedule ends Aug. 30 in Tennessee against the Titans, an exhibition opponent for the third time in five years.
Against the Seahawks, defensive tackle Sheldon Richardson will face his former team. And the Vikings will host a couple former defensive linemen in Seahawks Tom Johnson and Shamar Stephen. Both signed in Seattle during free agency last month.