FOXBOROUGH, Mass. – The offensive line struggled to keep Tom Brady upright in the New England Patriots’ last game. Fixing that could be a tough job in their next one.

New England will play Sunday against the Dallas Cowboys and their pass-rushing star, DeMarcus Ware, on the same field where the New York Jets sacked Brady four times. The Patriots still won 30-21 last Sunday.

But every hit Brady takes could threaten his health and the team’s welfare. And Ware, who has five sacks in four games, is the defender most likely to smack him.

“He can get after a quarterback as good as anyone we play,” Brady said Wednesday. “If he gets going early, he’s going to be a problem all day, so we’ve got to make sure we really account for him on every play.”

Ware had 80 sacks entering this season. He’s officially a linebacker but moves all over the field and can rush the passer from any spot. That ability requires offensive linemen to be especially alert.

Lose sight of him and your quarterback is likely to end up on the ground if he can’t get rid of the ball in time. Especially if that quarterback is Brady, who occasionally jokes about his lack of elusiveness.

Patriots left guard Logan Mankins knows he and his fellow blockers can’t afford another performance like the one against the Jets. Two of the four sacks came in the last two minutes of the first half.

“It was all breakdowns,” he said. “It was all mental stuff that shouldn’t have happened. We cut guys loose. We had them accounted for, we just didn’t get them. Anytime you make that many mental errors and they result in sacks, it’s disappointing.

“If you don’t learn from it, it’s going to happen every week and you’re not going to win making the same mistakes every week.”

In the first four games, Brady was sacked a total of four times. That’s the kind of blocking the Patriots (4-1) want again.

But the offensive line has new starters at three positions — center Dan Connolly, right guard Brian Waters and right tackle Nate Solder. Tackle Matt Light and Mankins are in their seventh seasons as starters on the left side.

In his only game against the Patriots, a 48-27 New England win in 2007, Ware had one sack. The Cowboys had three in the game, including one by Greg Ellis that forced a fumble that was returned for a touchdown by Jason Hatcher.

Patriots defensive end Andre Carter, an 11-year veteran, is impressed by Ware.

“He’s an all-around football player,” Carter said. “You can label him as a linebacker but he’s just a complete athlete. So why not use that level of athleticism to try to make plays and be disruptive? And it seems like he’s disruptive every play.”

Against a strong pass rush, it becomes more important for a quarterback to spot his open receivers quickly and get rid of the ball early to avoid being sacked.

“Anytime a quarterback is limited in the amount of time that he has to dissect a play or hold on to the ball, then you don’t make as good throws or as good reads,” Brady said.

Ware’s five sacks tie him for fourth in the NFL. The Cowboys (2-2) are tied for eighth in the NFL with 13 sacks. They also have Anthony Spencer with three sacks and Hatcher with two, although Hatcher missed the 34-30 loss to the Detroit Lions with a calf injury before last Sunday’s bye.

“They really get pressure on the quarterback from everybody,” Brady said.

But Ware is the most dangerous.

Ware “is one of the best players in the league,” Mankins said.