When considering the Vikings’ quarterback situation heading into 2018, much of the conversation — and rightfully so — is focused around Case Keenum, Teddy Bridgewater and Sam Bradford. All three have laid claim to the Vikings starting job at various points in the last three years, and all three are free agents. But it’s also not quite accurate to say every Vikings 2017 quarterback is a free agent, nor is it quite right to ignore one other passer who could be a factor: Kyle Sloter. That’s not to suggest Sloter is a dark horse candidate to be the team’s starting quarterback in 2018, but the Vikings have made it clear they like the undrafted former Northern Colorado quarterback. First, they paid him nearly triple the going rate to sign him to their practice squad in 2017 after the Broncos cut him at the end of the preseason.