49ers defensive end Nick Bosa is a four-time Pro Bowl selection and was the defensive player of the year in 2022. Godofredo A. Vásquez/Associated Press

FOXBOROUGH, Mass. — Patriots offensive coordinator Alex Van Pelt aptly described 49ers defensive end Nick Bosa as a “nightmare” while speaking to reporters Thursday morning.

49ers coaches would never be this brutally honest days before a game, but if Bosa is a “nightmare,” then facing the Patriots’ offensive line is a dream for San Francisco’s pass rushers.

The Patriots’ offensive line is already allowing the NFL’s highest pressure rate this season with quarterback Jacoby Brissett under siege on 46.4% of dropbacks. And it appears that they’ll be starting their fourth left tackle in as many weeks with Demontrey Jacobs, who was claimed off waivers from the Broncos in late August, working alongside left guard Sidy Sow, center David Andrews, right guard Layden Robinson and right tackle Mike Onwenu early in practice Wednesday and Thursday.

Bosa is a four-time Pro Bowl selection, the defensive player of the year and a first-team All-Pro in 2022 and perennially one of the best pass rushers in the NFL. He led all edge defenders with 121 total pressures last season while racking up 10.5 sacks, and he has 12 pressures and two sacks through three weeks this season.

Those totals are sure to increase this week with the Patriots on the docket, especially since he spends most of his time on the right side of the defense, rushing against the opposing left tackle.

“Great player, generational player,” Van Pelt said. “Speed, power, all of it. Definitely an issue. Definitely a concern. We have to make sure that we don’t let him ruin the game for us, because he is that type of rusher.”

A reminder of how the Patriots got to this point at left tackle: Executive Vice President of Player Personnel Eliot Wolf made the wise decision to allow Trent Brown to walk in free agency after the massive left tackle was openly discontent by the end of the 2023 season, but only signed Chukwuma Okorafor, a career right tackle, and drafted Caedan Wallace, a college right tackle, to replace him.

Okorafor worked at left tackle during the the spring, but the Patriots experimented with different combinations along the offensive line throughout the summer, trying Wallace and Vederian Lowe on Brissett’s blindside, as well. They finally settled on a combination of Lowe at left tackle, Sow at left guard, Andrews at center, Onwenu at right guard and Okorafor at right tackle until Lowe suffered an injury before the Patriots’ preseason finale and Sow hurt his ankle in that game.

That forced the Patriots to adjust and begin the season with Okorafor at left tackle, Michael Jordan at left guard, Andrews at center, Robinson at right guard and Onwenu at right tackle. Okorafor was benched 12 snaps into the season for Lowe, who had practiced just once leading up to the game. Okorafor then decided to leave the team the following Saturday and was placed on an exempt list. He’s since been moved to reserve/left squad and can’t return this season.

Lowe started Week 2 but suffered a knee injury late in the game, thrusting Wallace into action at left tackle. Wallace started Week 3 but suffered an ankle injury late in the game, bringing Jacobs off of the bench. On top of that, Jordan also suffered an ankle injury late in the loss to the Jets, but it appears Sow is now ready to return to his starting spot.

Through two practices this week, Lowe and Sow have yet to participate, and Wallace has been limited.

Jacobs, who entered the NFL as an undrafted free agent out of the University of South Florida last spring, allowed one sack in 11 pass-blocking snaps against the Jets.

The 6-foot-6, 315-pound offensive tackle said he’s excited by the prospect of facing Bosa.

“Just play with technique, honestly,” Jacobs said when asked the key to facing top-tier pass rushers. “It’s crazy, once you get in front of all of these good pass rushers, it’s kind of like a mental game. You’ve got to stay composed and play technique. That’s about it.”

Jacobs joined the Patriots just four weeks ago and is still learning offensive line coach Scott Peters’ striking system after spending the summer with the Broncos. He said the strengths of his game are playing with length and physicality and getting out of his stance. He’s also athletic for the position and tested well at his pro day last March, running a 5.17-second 40-yard dash with a 7.52-second 3-cone drill, 4.73-second short shuttle, 26-inch vertical leap, 9-feet, 4-inch broad jump and 22 bench press reps of 225 pounds.

Jacobs called Bosa a “very good pass rusher” who “doesn’t waste too much movement.”

Van Pelt said that the attrition along the offensive line will drive how the Patriots approach blocking Bosa.

“We have to be creative, have multiple ways of doing it,” Van Pelt said. “It’s something we’ve dealt with in the past. There’s ways to get it done. It’s going to be a group effort and take a lot of energy to block him in pass protection.”