Seymour

FOXBORO — With all eyes on Pittsburgh’s league-best defense, the Steelers’ offense is often lost in the mix.

The unit has run up the score against some of the league’s lesser lights, such as Cincinnati and Houston. But teams with strong pass rushes and powerful front sevens have further stacked the box and exploited the weakness on Pittsburgh’s offensive line — a formula the Patriots may employ tomorrow. The Eagles, Giants and Ravens, for instance, crowded men near the line of scrimmage earlier in the season, and forced quarterback Ben Roethlisberger to win the game. He beat Baltimore in overtime, but couldn’t top Philadelphia or New York.

That leaves the Patriots, with their excellent linemen and linebackers, licking their chops for a physical contest that could go in their favor.

“Our front seven is going to be challenged this week, but we feel like we have a good front seven, so hey, it’ll be man-on-man,” said defensive end Richard Seymour.

Pittsburgh has long held a reputation as a power running team that grinds out wins the old-fashioned way, yet that mantle can be difficult to bear without a dominant power rusher and a suspect offensive line. This year, Pittsburgh’s rushing offense is 25th in the league.

Pittsburgh’s offensive line returned only two starters from its 2007 squad, and then guard Kendall Simmons was lost for the season in late September. The only holdover, tackle Marvel Smith, has struggled with a balky back. Only recently, Roethlisberger said, has the line been able to find some consistency.

“I think the whole line is one of those special positions that you kind of need to have some cohesiveness” said Roethlisberger. “You need to know who’s to your right and to your left. When you’re rotating guys in and out, it can be tough at times. But we’ve had that same group of guys in there for the last couple weeks now and they’re really starting to understand and know each other.”

The Steelers also lack an established power rusher. With bruising rookie Rashard Mendenhall out for the season, the Steelers have relied on the speedy Willie Parker and his backup, Mewelde Moore. Neither man is a between-the-tackles battering ram, and with the struggles of the offensive line, the Steelers have, by necessity, started to spread the field more.

“If we are going to be good,” said Steelers coach Mike Tomlin, “we have to be capable of winning games in a lot of ways –– running it, throwing it –– and if we are going to be a complete offense, a complete team, we have to be able to do that. Ultimately, it’s about winning and losing for us.”

All this has produced some rough moments for Roethlisberger, who has dealt with a shoulder injury much of the season. He has 11 touchdowns and 11 interceptions for an 80.5 quarterback rating, second-lowest of his five-year career. But since throwing three interceptions against the Colts on Nov. 9, the Steelers’ quarterback said the offense has started to jell, partially because both he and the unit have concentrated on keeping turnovers to a minimum in the past few weeks.

“I think our offense,” said Roethlisberger, “we have kind of struggled throughout the year at times. But like I said, it’s about when you get hot and when do you start to put things together. The last couple of weeks we’ve done a pretty good job offensively of scoring points and not turning the ball over, and we just need to continue to do that.”

It is possible that the Patriots will follow the blueprint established in the Steelers’ losses to the Eagles and Giants: stack the box, stop the Steelers’ quick runners from getting outside, and make Roethlisberger prove that he is healthy and can avoid costly turnovers.

Head coach Bill Belichick is never one to give away his game plans, and he praised the offensive potential of his longtime rival.

“Offensively, running backs [Mewelde] Moore and [Willie] Parker have different styles that we have to be aware of. They have a great quarterback, very good skill players, tight ends, wide receivers — [Hines] Ward, [Santonio] Holmes, Heath Miller, [Nate] Washington. They are pretty well loaded and have a big offensive line.”

dbarbari@projo.com