Quarterback Case Keenum is reportedly expected to sign with the Denver Broncos when free agency officially opens on Wednesday.

Keenum has been allowed to hit the open market by the Minnesota Vikings despite leading them to the NFC Championship game last season.

His last-second touchdown pass to Stefon Diggs, dubbed 'The Minneapolis Miracle', sent the Vikings to the conference title game, where they were thrashed 38-7 by the Philadelphia Eagles. 

ProFootballTalk reported Keenum is expected to receive $18-20million a year from Denver.

The 30-year-old will look to help steer the Broncos to a bounce-back season after they went 5-11 in 2017.

Trevor Siemian, Brock Osweiler and Paxton Lynch all started games for the Broncos, the latter pair failing to win in any of their appearances in a miserable first year for head coach Vance Joseph.

Keenum, who has also had unsuccessful stints with the Houston Texans and Los Angeles Rams, went 11-3 in the regular season as a starter for the Vikings, throwing for 3,547 yards and 22 touchdowns with just seven interceptions.

The Vikings have no quarterbacks under contract for 2018 but have been linked with both Kirk Cousins of the Washington Redskins and Drew Brees, who has yet to be re-signed by the Saints.