I just don't see the Vikings winning this game. And that's a problem, because they need to. These last three games are all must win games if the Vikings are going to make the playoffs. The Steelers, however, aren't patsies like most of the teams on the Vikings' schedule. Let's go to the equation:
The Vikings need turnovers to win. The Steelers (with Roethlisberger under center) don't turn the ball over. Roethlisberger has only thrown seven interceptions this season, which is only two more then Ryan Fitzpatrick threw last week. The Steelers also have a great running game, which means that they're going to be less balls in the air for the secondary to have a shot at. And the Steelers are a quality team--they're 8-5 and that's in a much tougher AFC. In terms of the equation, the Vikings aren't going to get many turnovers (T is low), and the quality of their opponent is high (which means a lower number). That's not good for the Vikings.
If we look at the other half of the equation, we also see a bleak picture. The Steelers are holding opposing teams to 89 rushing yards a game. They aren't as strong in their pass defense, but they're still a middle of the pack team. I can't say that the Vikings having to rely on Brad Johnson to win a game makes me very confident either.
In conclusion, the Vikings aren't likely to create turnovers against the Steelers. The Steelers are going to shut down the Vikings' running game, and their pass defense isn't bad either. So when you plug the numbers in, unlike in previous weeks, the Vikings Victory Equation returns a pretty low number, which means it's likely to be a long weekend.