The toughest assignment of Zach Strief’s season is lurking Sunday.

For the most part, on nearly every snap, Strief will line up and stare across the line of scrimmage at J.J. Watt, the transcendent defensive end who has made the title of the NFL’s best defensive player anything but arguable in the past couple of seasons.

Watt, the only player in NFL history with multiple 20-sack seasons, is on his way again, tied for the NFL lead with 11.5 sacks, a whopping 21 tackles for loss and 34 quarterback hits, two numbers that dwarf the NFL’s second-best in those categories.

The reigning Defensive Player of the Year usually lines up on the left side of Houston’s defense, putting Strief squarely between Watt and quarterback Drew Brees.

“I think I’ll probably see him more than anybody,” Strief said. “Percentage-wise, that’s where he’s been, but they’ll move him all over.

“Obviously, look, when you have a player like that, teams throw a lot of stuff at him to slow him down, they move him into areas where you’re not expecting him.”

Teams have tried a little of everything this season to slow down Watt.

Houston’s best player has been triple-teamed at times, chipped and doubled at others, the focal point of every team’s offense when Houston arrives on the schedule.

New Orleans likely will employ the same tactics. Strief has intermittently struggled against pass rushers this season, normally giving up sacks off the edge to speed rushers who can turn the corner.

Watt’s a different kind of challenge altogether. If Strief’s going to slow him down, the veteran tackle knows he’s going to need some help.

“Any team and every team (uses more than one blocker on Watt),” Strief said. “You can see every week what team’s plans are for him — and we’re going to be no different. It’s going to be a group effort, because he’s an elite player, and he creates some problems.”

New Orleans would probably like to be able to match up its best offensive lineman against Watt, similar to the way teams sometimes ask their best cornerback to shadow the opponent’s No. 1 receiver on every snap.

But this is the offensive line, and Armstead, who is having a Pro Bowl-caliber season despite battling a knee injury, likely will only get a handful of snaps against No. 99. Houston likes to move Watt around, but he mostly operates against the opponent’s right tackle.

“It depends on the team,” Armstead said. “I guess it’s their game plan (that determines) how much he moves around. I watched three games, and it wasn’t too often (that Watt lined up against the left tackle. With the way that Whitney Mercilus and (Jadeveon) Clowney are playing, he really doesn’t have to move around as much.”

Mercilus, in particular, has presented big enough problems for left tackles around the league this year. The veteran already has 6.5 sacks, only a half-sack off his career high. And he has been kept fresh by former No. 1 pick Clowney, who has 1.5 sacks.

Armstead likely will spend most of his afternoon trying to keep Watt’s running mates from creating even more havoc.

“Having a guy like J.J., a lot of guys double-team him, so that means one-on-one with Clowney and Mercilus,” Armstead said.

And it’s not just the tackles who have to worry. Houston sometimes shifts Watt inside — the same way the Saints do with Cameron Jordan — in passing situations, and all of the shuffling is paying off. Houston, which has held its past three opponents to fewer than 300 yards, leads the league in third-down defense.

“When they get into their sub-packages, they have the freedom to put him wherever they want to create a matchup,” Saints offensive line coach Bret Ingalls said. “It’s difficult because, when you normally study an opponent, the player, we’ll study the techniques that a given guy might get, or two guys, but everybody’s got to study him and prepare for him: If he lines up on them, what can you expect? He’s got versatility in his pass rush, and I think that’s what makes it so hard on the offense.”

Finding No. 99 is only the first step. Once the ball is snapped, Watt brings an unmatched combination of speed, power, tenacity and lateral quickness, making him an unstoppable force inside. New Orleans will try to hold him off as long as possible.

Then it’s up to Brees to get rid of the football before Watt can ruin the play. Watt has a sack in seven of his 10 games this season; it’s not a question of if Watt will get home, it’s when.

“He might be blocked for a short while, but eventually he is going to find a way,” Brees said. “You just want to make sure that the ball is out.”

Watt spends most of his life making that simple task incredibly difficult.