Three of the best possible free agents are no longer available anymore. The best offensive tackle, Jordan Gross re-signed with Carolina and the best cornerback, Nnamdi Asomugha, re-signed with Oakland. The latter was a move clearly designed by Asomugha and his agent to assure that he wouldn't be franchised by the Raiders for the rest of his career, as it includes an out clause after the 2010 season. In other, unhappy news, the second best corner on the marker, Dunta Robinson, was franchised by the Texans. He was probably the only potential target for the Vikings to be franchised (aside from Cassel, of course), though a few other players, such as RB/Returner Darren Sproles of the Chargers, OT Max Starks of the Steelers and WR Antonio Bryant of the Bucs might have been interesting signings had they not also been franchised.
While there are still some linemen worth pursuing in free agency (more on that later), the best way for the Vikings to address their need for depth at corner is now through the draft.