Football fans love to see two division rivals face off with something to prove. But it’s not business as usual this weekend in the NFL’s northern divisions. It’s been a long time since the “something to prove” in a Green Bay-Minnesota matchup was “which team is less pathetic,” and it’s been even longer since Cincinnati found itself playing for a two-and-a-half game division lead.

STEELERS (3-2) AT BENGALS (5-1)
(Sunday, 1 p.m.)

The upstart Bengals can show they are a true Super Bowl contender. The Steelers must avoid dropping to .500. In a game of this magnitude, it would be nice if both teams were at full strength, but injuries will play a major factor in determining the winner.

Last week, Steelers quarterback Ben Roethlisberger and star receiver Hines Ward watched from the sidelines as backup Tommy Maddox turned the ball over four times in a loss to Jacksonville. Roethlisberger will return this week, but Ward remains a question mark. His absence would be a major blow to the Pittsburgh offense.

But the most important injuries for Pittsburgh are not on the offensive side of the ball.Two of Pittsburgh’s top three cornerbacks, Deshea Townsend and Ricardo Colclough, are injured and unlikely to play.That leaves one starter,IkeTaylor, to defend Chad Johnson, probably the best receiver in the NFL today. Not only is Johnson almost impossible to defend, he’s also not the only option for quarterback Carson Palmer, who will be unafraid to target his other receivers if Pittsburgh’s part-timers can’t cover them. Rounding out Cincinnati’s balanced offense are Rudi Johnson, who’s averaging 91 yards per game on the ground, and third-down back Chris Perry, who has emerged as a major receiving threat out of the backfield.

It will be important for Palmer to have enough time to find his receivers down field, and the battle around the line of scrimmage pits strength against strength. Cincinnati’s offensive line has the league’s second-lowest Adjusted Sack Rate, a measure of sacks per pass play adjusted for down, distance, and opponent.These five linemen will have to block Pittsburgh’s defensive front seven, which has the league’s thirdhighest Adjusted Sack Rate.

If the Steelers want to keep the ball out of Johnson’s hands, it will be easier to keep the ball away from the Bengals’ offense altogether by dominating time of possession. Pittsburgh running backs have carried the ball an average of 28 times per game, which puts the Steelers in the NFL’s top five, and they led the league in carries last year.

Cincinnati’s clear defensive weakness plays right into Pittsburgh’s preferred style of play.The Bengals cannot stop the run.They tried to fix this issue in the offseason, and their wins have somewhat masked the problem because opponents fell behind and had to abandon the ground game. Nonetheless, the Bengals stuff opposing runners at the line less often than any other team and give up the most conversions on third-and-short. Since the Bengals are especially poor on runs up the middle, they’ll get a big dose of veteran Jerome Bettis, but they’ll also see plenty of the younger and shiftier Willie Parker. Pittsburgh will get yards on the ground, but they’ll need to get points there as well to overcome Cincinnati’s advantages in both health and home field.

PACKERS (1-4) AT VIKINGS (1-4)
(Sunday, 1 p.m.)

Quarterbacks and running backs get the glory while offensive linemen stay mostly anonymous. But this game is a lesson in the domino effect that can occur when a subpar blocker replaces a good one.

Green Bay lost guards Mike Wahle and Marco Rivera to free agency, while Minnesota lost center Matt Birk to injury and guard David Dixon to retirement. Both offenses have fallen apart this season, except against New Orleans – the team that represents each team’s only win.The Packers offensive struggles haven’t gotten the same press as the Vikings’ because their win against the Saints was bigger and more recent.

According to Football Outsiders’ Defense-adjusted Value Over Average (DVOA) ratings – which break down each play of the season and compare it to the NFL average based on situation and opponent – Green Bay’s offense has dropped from eighth in 2004 to 16th this season. Minnesota’s drop has been even more severe, from third to 29th.Without these stalwart linemen, neither team can run the ball: DVOA ranks Green Bay 27th in run offense, Minnesota 29th.

Much of this game will turn on the question of which team’s mediocre front seven will be able to penetrate the other team’s porous blocking. But the ball will get into the air at some point,where Minnesota has an advantage. DVOA ranks the Vikings eighth in pass defense, but the Packers just 23rd. Cornerback Fred Smoot seems to be the only one of Minnesota’s big-name off-season acquisitions to make a real difference: the Vikings have allowed just nine receptions over 20 yards, and just 23 receptions between 11 and 20 yards. Both numbers rank fourth in the league.

The Vikings have been quite susceptible to the underneath pass, however. With Packers tight end Bubba Franks questionable with a knee injury, look for a big play by Favre’s new secret weapon, David Martin, who already has two touchdowns this year.

Wideout Nate Burleson was supposed to replace Randy Moss as Minnesota’s top weapon, but he’s been injured, and the Vikings are counting on his return to jump-start their passing game. But Green Bay’s pass defense has put up extremely odd numbers. The Packers are the best team in the league against no. 1 receivers, keeping Carolina’s Steve Smith and Detroit’s Roy Williams to less than 15 yards apiece. But they get slashed by pretty much everyone else. That means Burleson’s comeback could end up as the coming out party for someone like rookie receiver Troy Williamson.

You may have also heard that Minnesota is having some sort of off-field problem involving a boat. In a division where no team is better than 2-3, it is hard to say that the loser of this game can pack it up for the season. But given their legal distractions, a Minnesota loss at home would come pretty close.

Mr. Schatz is the editor in chief of FootballOutsiders.com.