Brett Favre and the Minnesota Vikings exploited one of the AFC North's supposedly daunting defenses to remain undefeated last week, and facing the defending Super Bowl champions certainly doesn't provide time to relax. The Vikings' biggest obstacle, however, might be the Pittsburgh Steelers' offense. Favre and Ben Roethlisberger will be the focal points in their first career meeting Sunday at Heinz Field, where Minnesota will likely need a better effort from its defense - formerly led by Steelers coach Mike Tomlin - to stay perfect. When Favre opted out of retirement for the second time in August, the Vikings (6-0) were looking for a caretaker at quarterback to avoid turnovers and let Adrian Peterson and their vaunted rushing attack lead the way. Peterson hasn't disappointed - he leads the league with 624 rushing yards and has seven touchdowns - but Favre has done more than hand him the ball and get out of the way. The three-time MVP is the league's third-highest rated passer (109.5) and has thrown 12 touchdown passes with just two interceptions - the fewest in any six-game stretch of his career. Favre threw for 278 yards and three touchdowns Sunday in a 33-31 win over the Ravens, which Minnesota survived thanks to a missed field goal as time expired after giving up 21 fourth-quarter points. "Well you know (Brett's) been to a few of those rodeos before," Vikings coach Brad Childress said. "Ahead, behind, he knows what he's doing with the football in this system." Peterson ran for 143 yards, part of the season-high 426 total yards for Minnesota, but the Vikings gave up 448 yards and seemingly had no chance to stop Baltimore in the fourth quarter. "It wasn't a meltdown because we didn't lose, but it was pretty close," defensive end Jared Allen said. That bodes well for Pittsburgh (4-2), which has the league's fifth-ranked offense (403.7 yards per game) and has particularly excelled through the air. Roethlisberger is second in passing yards per game (314.5), and is right behind Favre in passer rating (104.5). He threw for 417 yards Sunday against Cleveland - the second-highest total of his career - and tossed touchdown passes to Heath Miller and Hines Ward in a 27-14 victory as the Steelers gained 543 total yards. "He's in total command of the offense," said Tomlin, who was the Vikings' defensive coordinator in 2006 before being hired by Pittsburgh in 2007. "It's fun to watch." Tomlin didn't have Allen anchoring his defensive line then, but Minnesota is thrilled to have him now. An All-Pro in each of the past two seasons, Allen has 7.5 of the Vikings' league high-tying 21 sacks. Roethlisberger, meanwhile, has been sacked 155 times since the beginning of 2006 - by far the most in the NFL. If Allen and perennial Pro Bowl tackles Kevin and Pat Williams can't get in the backfield, however, the Vikings could have problems. Top cornerback Antoine Winfield sprained his right foot in the second quarter against the Ravens and is listed as doubtful. That could give Ward, first in the league with 599 receiving yards, and Super Bowl XLIII MVP Santonio Holmes, eighth with 438, room to run in the secondary. Pittsburgh lost a significant member of its defense, run-stuffing end Aaron Smith, with a season-ending shoulder injury suffered Oct. 11 against Detroit, but it welcomed another important piece back against Cleveland. Safety Troy Polamalu played for the first time since injuring his knee in Week 1 against Tennessee, and he recorded his second interception against the Browns. Polamalu and the rest of the defense will certainly have its eyes on Peterson as it tries to keep its 24-game streak of not allowing a 100-yard rusher intact. Favre, though, has some emerging weapons at his disposal on the outside. Third-year receiver Sidney Rice is Minnesota's deep threat, and his 409 yards through six games are already a career high. "You can't focus on one thing," Steelers linebacker LaMarr Woodley said. "If you focus on the run, Brett Favre will beat you downfield with guys like Sidney Rice. If you focus on the pass, Adrian Peterson can run the ball. You have to balance it out and maybe try to stop both." Rice had six catches for 176 yards against the Ravens - including a 58-yard grab on the game-winning drive. "I've never had a guy like Sidney who can make those types of plays," Favre said. "It's a luxury." The Vikings' big-play receiver in waiting, though, might be sidelined Sunday. Rookie Percy Harvin left the Baltimore game after aggravating a left shoulder injury, and he's been limited in practice. Even Peterson, who Tomlin called "arguably the best football player in the world," was banged up against the hard-hitting Ravens, though a twisted ankle isn't expected to affect his status against the Steelers. Perhaps the biggest question mark in terms of personnel for Pittsburgh this week was the status of kicker Jeff Reed, who was cited for four charges after allegedly scuffling with police officers outside a bar near Heinz Field last Sunday. It's the second off-field incident involving Reed this year. Tomlin, however, said he won't suspend Reed. The Vikings, who were last 7-0 in 2000, lead the all-time series 8-6.