As left tackle for the New Orleans Saints, Terron Armstead is well aware of how devastating the Lions’ pass rush has been through six games this season.

But he couldn’t stop himself from raising an eyebrow in awe at his locker Thursday when he was informed how many pressures or sacks the Lions have produced the 232 times opposing quarterbacks have dropped back to pass against them this year: 109, according to the analytics website Pro Football Focus.

That means quarterbacks facing Detroit (4-2) have been hit, hurried or tackled behind the line of scrimmage one out of every 2.13 times they dial up a throw.

“Shoot, man — statistically, that is a lot,” Armstead said, three days before the Saints (2-3) were to visit an astounding Lions defense that was giving up the league’s fewest total yards, passing yards and points while recording the most sacks (20) as of Thursday. “Those guys — they are relentless. Throughout the entire play, they’re going to be trying to get to the quarterback.”

The Saints could opt to rely on quick screens and a running game that ranks eighth in the NFL.

Regardless, it’s hard to gauge the Saints’ odds of containing the Lions pass rush at Ford Field on Sunday.

Drew Brees, on one hand, has been taken down behind the line of scrimmage only four times in five games. That has him on pace to take fewer than 13 sacks this year, which would be the second lowest number of his 14 regular seasons as a pro and would be significantly down from the career-high 37 he took in 2013.

Saints coach Sean Payton gave some of that credit to an offensive line whose starters are second-year man Armstead, two-time Pro Bowl left guard Ben Grubbs, one-time Pro Bowl center Jonathan Goodwin, four-time first-team All-Pro right guard Jahri Evans and veteran right tackle Zach Strief. Third-year backup tackle Bryce Harris filled in for Armstead in Week 4 when Armstead suffered a concussion, and Tim Lelito — in his second season — subbed in for Goodwin, who left a pair of games hurt.

Payton gave the rest of the credit to Brees releasing the ball faster than would-be sackers have been able to converge on him.

“Obviously, that’ll be an important element in this game,” Payton said of Brees’ timely release and the offensive line’s performance.

Yet other factors are a cause for concern.

For one, as is expected to a degree, Brees’ commitment to avoiding sacks at almost all costs has backfired in big ways in some spots this season.

He tossed two interceptions in a 37-31 victory at home against Tampa Bay on Oct. 5 as he was falling down several yards behind the line of scrimmage because of pressure — one was returned for a score, and another resulted in a touchdown drive against the Saints. In retrospect, it was probably preferable for Brees to take a sack and not hastily fire off a throw that resulted in another pick-six during a Week 2 defeat at Cleveland.

However, the most pressing matter is a Detroit defensive line that’s unlike anything encountered yet by the Saints — which is saying something, considering they dealt with All-Pro defensive tackle Gerald McCoy when they beat Tampa Bay before their Week 6 bye.

The Lions have gotten 11½ of their 20 sacks from defensive ends Ziggy Ansah (4½) and George Johnson (four) as well as defensive tackles Ndamukong Suh (three) and Nick Fairley (one). Those four starters have produced 41 of Detroit’s 89 pressures, according to Pro Football Focus.

“It all starts with their front four,” Brees said. “Those guys are beasts.”

That couldn’t have been more vivid than it was in their 17-3 win at Minnesota this past Sunday, when Ansah, three-time first-team All-Pro Suh and Johnson combined for six of the Lions’ eight sacks. Ansah earned the Defensive Player of the Week, and the Lions sent a message the Saints clearly received.

“They’re big, strong guys, and they have been getting to the QB,” Evans said of a line whose average height and weight is 6 feet, 4½ inches and 288½ pounds. “We ... have to make sure we get our hands on these guys, be strong on our hands and not get pushed back.”