MINNEAPOLIS -- As the Minnesota Vikings head out to Arizona to face the Cardinals on Thursday night, they're going to have to face the league's top-ranked offense without the same key defenders who were missing during Sunday's 38-7 loss to the Seattle Seahawks.

The Vikings ruled out safety Harrison Smith, linebacker Anthony Barr, defensive tackle Linval Joseph and safety Andrew Sendejo for Thursday's game, meaning they'll be without arguably their top player at three levels of their defense (Joseph, Barr and Smith), as well as their other starting safety in Sendejo. Safety Robert Blanton is questionable for the game, and if he's healthy, he figures to start. If he's not, the Vikings' last line of defense could be rookie free agent Anthony Harris, whom they called up from their practice squad, and Shaun Prater, whom the Vikings brought back this week after carrying him on their roster the last two seasons.

Thursday night would have been a tough test for the Vikings even if their defense was completely healthy, and the game against the Cardinals won't have final say in their playoff hopes. The Vikings' two upcoming home games against the Chicago Bears and New York Giants will go much further toward answering that question, and both games look winnable for Minnesota. A win on Thursday against the Cardinals would effectively squelch questions about how good the Vikings really are, and if they're able to win without Joseph, Barr and Smith, it will be to their credit.

Otherwise, the Vikings' best course of action is to hope they can get their defense back to full strength by the time they play the Bears on Dec. 20.