Brown, 37, suffered a shoulder injury in practice on Monday and was held out of team activities for the rest of the week.
The 15th-year veteran was ruled out for Sunday's season opener against the Baltimore Ravens on Friday, but his injured reserve status opens a roster spot for the Jets.
Brown's is just the latest injury for a New York team trying to escape the AFC East cellar.
Brown was signed to a two-year, $22million contract last month after tackle Mekhi Becton was shut down for the season with a fractured right kneecap.
Jets starting quarterback Zach Wilson will miss at least three games as he recovers from surgery to repair a non-contact knee injury suffered in a preseason game. Joe Flacco will start under center in the meantime.
Brown was a First-Team All-Pro choice in 2012 and has been selected to five Pro Bowls while playing for the Houston Texans and Seattle Seahawks.
Brown, who earned a fifth career Pro Bowl nod last season with the Seattle Seahawks, can earn up to $22million over the duration of the deal, according to ESPN.
The Jets’ interest in the 14-year veteran increased after expected starting right tackle Mekhi Becton sustained a season-ending knee injury during Monday’s training camp practice. The 2020 first-round pick missed all but one game last season after dislocating his right kneecap in the team’s opener.
Brown, who turns 37 later this month, has been a more durable player over the course of his lengthy career, having played in every game in three of the past four seasons and missing just four over that span. His 203 career starts are the most of any active offensive lineman.
All of those starts have come at left tackle, where Brown could remain if the Jets opt to move starter George Fant back to the right side.
Fant, a team-mate of Brown with the Seahawks in 2018, began last season as the Jets’ right tackle before switching positions following Becton’s injury. The Jets decided to keep the six-year veteran at left tackle this offseason while moving Becton to the right side.
Brown broke into the NFL as a first-round pick of Houston in 2008 and earned first team All-Pro honours with the Texans in 2012. He spent nine-plus seasons in Houston before being traded to Seattle during the 2017 campaign following a contract dispute.
Brown has only a single year remaining on his existing contract, which will count for $13.35million against the cap in 2021.
The veteran lineman is keen for an extension, though, and he has the backing of superstar quarterback Wilson.
"Not having Duane Brown out there is a pretty significant deal because I think he's one of the best left tackles in the game, there's no arguing it," Wilson said.
"I think he's as good as it gets. There's nobody more athletic, more talented than he is."
Brown turns 36 this month, but the QB added: "Age is just a number. He looks like he's 28, 30 out there. He's really exceptional.
"He's so smart and physical, understands the game, and I think people fear him, to be honest with you, when they're rushing him and playing against him.
"So we definitely want to be able to get him back out there. We've got to figure that out because we need Duane Brown."
The issue and Wilson's comments should be of particular concern to the Seahawks, who for a time looked as though they might enter this year without the eight-time Pro Bowl quarterback.
Wilson this offseason bemoaned "getting hit too much", prompting speculation after an impressive 2020 went off the rails fast.
The 32-year-old, who had appeared on course for an MVP year, suffered as he was sacked 47 times for 301 yards, ranking third and second in the league respectively.
It is a common issue for Wilson, who has lost more sack yards (975) over the past three seasons than any other QB.
However, of those 146 sacks, Brown has allowed just six, showing why Wilson is desperate not to disrupt the one position that is performing in front of him.
Wilson believes Brown can continue to perform well into his thirties, too.
"I think he's got several more years to play," Wilson said. "I think he can definitely do it. I don't think there's anybody more athletic than him. You see what he can do.
"And he's also our leader. He's a guy who really leads the offensive line and, really, he commands the offensive line and really can set the tone."
Any regression in 2020 was minimal, as Brown allowed only a single sack for a second successive year and had just one penalty.
The former Houston Texans tackle allowed four adjusted sacks – up from one – but that still accounted for a mere 0.9 per cent of his 444 pass protection snaps, ranking 12th in the league among left tackles. His 0.4 per cent of 250 snaps had ranked fourth a year earlier.
There was no change, meanwhile, in the pressures Brown allowed, staying at 5.2 per cent – sixth in the NFL in 2020 (23 pressures allowed) and tied-second in 2021 (13).
Brown had abstained from practice for most of the Seahawks offseason programs in search of a new deal.
The two parties have come to terms on an arrangement that means Seattle quarterback Russell Wilson will have his best pass protector when the Seahawks face the Indianapolis Colts on Sunday.
According to multiple reports, Brown's deal has been adjusted so that per-game roster bonuses now take the form of guaranteed money. The Seahawks have also inserted an injury protection benefit for 2022.
While Wilson complained of getting hit too much in the offseason, little of the Seahawks' struggles to protect him were the fault of Brown, whom the Seahawks acquired in a trade from the Houston Texans in 2017.
Indeed, Brown's pressure rate allowed of 5.2 per cent ranked sixth in the NFL last season, though Wilson was sacked 47 times, the third most in the league.
With his financial demands satisfied, Brown can now focus on making sure Wilson has more time to throw this season, starting against a Colts team whose 39 sacks for negative yardage ranked tied-10th in the league in 2020.
