Control the three-man line of the New England Patriots .

The task will not involve the same amount of fun and relaxation as last weekend. But it most definitely will go a long way toward the Steelers ending a four-game losing streak in Foxborough, Mass., and maintaining their one-game lead over the Baltimore Ravens in the AFC North.

And that could prove to come with a higher price tag than the bill Roethlisberger footed for his linemen.

"They have a real physical defensive line and they got first-rounders across the board, and then their game plan is always a tough one," said guard Darnell Stapleton. "Their game plan seems like it's the never the same from the week before. You have to be ready for everything when playing those guys."

This will be the first time Stapleton, an undrafted free agent in 2007, will face the Patriots. Same with left guard Chris Kemoeatu. And it will be the first time Hartwig, a seventh-year center, will face them with the Steelers.

They compose the interior of the offensive line, the area that will be largely responsible for handling the Patriots' three-man front -- defensive ends Richard Seymour and Ty Warren and 325-pound nose tackle Vince Wilfork, all former No. 1 picks.

"Those No. 1 picks up front are horses," offensive coordinator Bruce Arians said.

Everything the Patriots do appears to revolve around the ability of the defensive linemen to stuff the run and pressure the quarterback. Complicating matters is the number of different defensive looks presented by coach Bill Belichick, the master of disguise.

"That's one of the biggest strengths of their defense," Hartwig said. "They run a lot of different fronts; they do a lot of things to try and confuse the offense, and they throw in new wrinkles every week. They'll throw you something you've never seen.

"We really have to be prepared for everything. At this point of the season, at some point in time, we've had just about every different defense thrown at us. But the thing with the Patriots, they do just about everything. It will be a challenge to figure out what they're doing."

And, just as he seems to be entrusted to do nearly every week, Hartwig has the chore of containing the nose tackle, in this case Wilfork, a Casey Hampton-type whom Hartwig said is equally hard to move.

Since coming to the Steelers in free agency from the NFC Carolina Panthers, Hartwig has had a steady diet of mammoth nose tackles in the AFC -- Baltimore's Haloti Ngata, Cleveland's Shaun Rogers and San Diego's Jamal Williams, to name a few. He gets another in Wilfork, the anchor of a Patriots run defense that allows 100.2 yards per game, 13th in the NFL.

"He's kind of similar to Shaun Rogers in that he has a real massive body and he's real explosive and powerful," Hartwig said. "He's probably bigger than Jamal Williams, but he's cut out of the same mold of all those other guys. He's able to take centers and physically dominate them at times. If I take a wrong snap or I get leaning one way, he could do some damage."

One of the obscured aspects of the Steelers' 34-13 loss to the Patriots last year was that the Steelers rushed for 181 yards -- 124 by Willie Parker. He is expected to play in the 4:15 p.m. game Sunday despite inflammation in his left knee -- the same knee that was sprained and caused him to miss four games earlier this season. Parker practiced yesterday for the first time this week.

If he can't play, Parker will be replaced by Mewelde Moore, who has started four games and is second on the team with 432 yards rushing on 109 attempts. Moore leads the team with six touchdowns, including five rushing.

Moore faced the Patriots just once when he was with the Minnesota Vikings and produced two big plays in 2006 -- a 71-yard punt return for touchdown and a 50-yard catch.

"They give you all kind of looks and they got the personnel to do it," Moore said. "That's one of things the mastermind over there, Belichick, was thinking about when putting the defense together. He was thinking about making sure he can give you an array of different looks that you have to prepare for."

Also, the Patriots have had problems sacking the quarterback (21 sacks) because of the loss of outside linebacker Adalius Thomas (broken forearm) and a nagging shoulder injury to former Steelers outside linebacker Mike Vrabel -- two of the top five sackers among active NFL linebackers. Seymour leads the team with seven sacks and 13 quarterback hurries.

That has caused problems for the secondary, which lost Pro Bowl safety Rodney Harrison (thigh) to a season-ending injury and has had to rotate several cornerbacks, the latest being former Bengal Deltha O'Neal. The Patriots rank 18th in the NFL in pass defense, allowing an average of 215.8 yards per game and giving up an AFC-high 19 touchdowns.

"I think they're capable of [confusing an offense]," said tight end Heath Miller.

"But you can get caught up in a variety of different looks they give you and not worry about the things they do the other 80 percent of the time."