PITTSBURGH — This is why the Minnesota Vikings spent the summer persuading Brett Favre to end his latest retirement: to run their offense, not be their offense.

To show them how to win big games, especially those in difficult road settings such as Pittsburgh. To complete the passes that must be completed in the games that can't be lost. They wanted him to be Ben Roethlisberger.

There are numerous subplots to today's game between the Vikings (6-0) and Steelers (4-2), one that matches a team playing like a champion against one that's proven twice in the past four seasons it is a champion.

Can NFL rushing leader Adrian Peterson break off runs against one of the best defenses of its era? Can a getting-healthy Troy Polamalu disrupt one of the league's best-balanced offenses? Can the Steelers' improved offensive line handle the Vikings' run-controlling defensive front?

Ultimately, it may come down to what nearly everyone wants to see: Can a still-young quarterback who's already won two Super Bowls prevent an ageless quarterback he admired as a youngster from taking a small but significant step toward winning his second?

Roethlisberger, 27, leads the NFL in yards passing, something no Steelers quarterback has done for a full season since the 1970 merger.

"A young Brett Favre," Vikings coach Brad Childress said of Pittsburgh's "Big Ben."

Curiously, the 40-year-old Favre is becoming more like Roethlisberger, a player whose most impressive stat is his winning percentage.

"I've just practiced and gone about it as (if) I was 25," Favre said.