A source tells Profootballtalk that free agent Michael Vick could become a serious option for the Vikings if they fail to re-sign Matt Cassel. Outside of Adrian Peterson, it's the first time Vick has been linked to the Vikings. He'd make the Vikes more competitive than Cassel, but would be a far poorer bet to stay healthy. The league's anonymous sources have yet to identify a favorite for Vick's services.