Getty Former Minnesota Vikings quarterback Case Keenum. The Minnesota Vikings likely need to add another quarterback behind J.J. McCarthy , even after Sam Howell showed out against the Houston Texans in the team’s preseason opener over the weekend. Howell went 11-of-13 for 105 yards through the air and posted a QB rating of 100.3 in Minnesota’s 20-10 victory, but that doesn’t erase the two weeks of struggles he has had throughout training camp or the fact that the coaching staff benched him