They are all simply linemen. Not necessarily interchangeable, but put in ever-changing positions along the line.

Being a member of the D-line unit in New England means something different from game to game and often series to series: different alignments, different starting groups, different rotations, depending on the opponent and situation.

Consider: In 14 games this season, the Patriots have had a different starting defensive line in every game. Last week against Green Bay, it was Wilfork at left end, Gerard Warren at nose, and Eric Moore at right end; in Chicago, Warren was at right end opposite Wilfork, with Ron Brace at nose tackle.

The games against the Colts and Lions called for just two down linemen at the outset, as the Patriots went with four linebackers and five defensive backs.

In the season opener against the Bengals, New England started in a 4-2-5 alignment, with Brace and Mike Wright at the end spots and Wilfork and Myron Pryor at the tackles.

These days, the versatility and experience of players lining up in different spots has become a benefit.

New England’s depth on the D-line has been tested over the last month-plus. Pryor is out again today for the seventh week with a back injury, and Wright will miss his fifth straight game with a concussion. Brace who missed last week’s game against Green Bay, also with a concussion, is questionable.

And the line took a big hit before the season even began when Ty Warren was placed on injured reserve with a hip injury.

But the line keeps rolling on.

“It’s everybody just knowing their role,’’ Wilfork said. “You never know when you’ll have to go in the ballgame and have to step up. You never know, but we say, ‘When your number is called, you have to be ready to respond.’ ’’

Wilfork is the epitome of that sentiment, particularly this season.

He is the only lineman to have started every game, but his starts and snaps have come all over. When the Patriots use their base three-man line, sometimes Wilfork is at nose, but other times he could be an end. Sometimes he’s lined up over the center’s left shoulder and others his right; sometimes he takes on the left offensive tackle and sometimes he flips to the right.

Against the Packers, he played a season-high 75 (out of 84) snaps. Bill Belichick praised the effort as one of the best games Wilfork has had in his six seasons with New England.

“It’s fun, it’s very fun,’’ Wilfork said of moving around. “But at the same time, it’s challenging. I play every position on the defensive line.

“It’s very different at times, especially when every week your opponent is different. I think for me to go out and play different positions, it just shows the young guys that if you commit to what we’re doing, you’ll be OK.’’

Like the rest of the defense, there are new faces on the line as well. Rookies Brandon Deaderick and Kyle Love have become part of the rotation, and Brace and Pryor are each in their second season.

They, like Gerard Warren, who arrived this year after nearly a decade spent with other NFL teams, learned early on that there is no such thing as having one responsibility with this defensive line.

“I think that anytime you’re on a football team, you want to learn more than one position anyway, just in case,’’ said Pryor. “You might be a primary nose tackle but you’re a secondary defensive end — you have a backup role, too.

“So it’s always important to know not just your position but know a position that you might play, too.’’

In the big picture, there’s a benefit to knowing as much as possible.

“If you just know your position and you don’t really know the other positions, then when things are being run, you don’t really know what’s going on with that guy [next to you] so you always want to study two positions so you know everything that’s going on,’’ Pryor noted.

But it isn’t as if Deaderick started learning more when Wright went down, or Love began spending more time in his playbook when Pryor got hurt. They started before that.

“You really get that background at the beginning of the year,’’ said Belichick. “It is hard in the middle of November to start teaching something new.

“You really want to have a good foundation and background for it, and that starts in the spring and in training camp and in the preseason where you can not only teach it in the book or on the blackboard or in a walk-through but you can actually get reps at it, full speed with guys blocking, pulling, pass-protecting and really seeing things at the kind of tempo or close to it that they would have in the game.’’

The Patriots take the field in Buffalo today without Deaderick, who was hit with the double whammy of a shoulder injury and the flu this week and missed two days of practice.

Whoever is out there, however, will be ready and able.

“It’s just preparation,’’ Wilfork explained. “Just knowing what you’re on the field doing. You can’t put somebody out there on the field if they don’t know what they’re doing.’’

Shalise Manza Young can be reached at syoung@globe.com. Follow her on Twitter @shalisemyoung.