Brown, 37, who signed a two-year, $20 million contract Aug. 15 to replace the injured Mekhi Becton (out for the season), suffered a shoulder injury in Monday's practice and could be headed to injured reserve, according to coach Robert Saleh.
The Jets are evaluating test results and soon will make a decision on whether to place Brown on IR, which would sideline him for a minimum of four games.
The news comes only two days after the Jets announced that quarterback Zach Wilson will miss at least the first three games as he continues to recover from arthroscopic knee surgery. Early in training camp, Becton injured his right knee in practice, requiring surgery.
Brown's injury forces yet another shuffling of the tackle positions, hardly an ideal situation with the opener so close.
Right tackle George Fant, who began camp at left tackle, will move back to that position.
"Obviously, I'm frustrated," he told reporters Friday. "It's the second time I've had to move the week of a game. I can't control it, but it's obviously a frustrating situation."
Until this week, he hadn't practiced there since the first week of August, but it's his natural position and it should be a relatively seamless transition.
"I'm sure it's frustrating for George -- everyone just wants to settle into their job -- but credit to George," Saleh said. "He's an uber-athlete, he's got great versatility and he's always been a team-guy first. ... Him going to the left side this week, he's making it very easy for this transition to happen."
The big question is right tackle. Rookie Max Mitchell, a fourth-round pick from Louisiana, will get the start. Ordinarily, it would've gone to career backup Conor McDermott, but he missed the preseason because of an ankle injury. McDermott practiced this week on a limited basis, but he is bound to be rusty.
Mitchell was drafted as a developmental prospect, and the plan was to have him gain seasoning for a year on the bench. The plan changed. He got a lot of work in the preseason (a team-high 117 offensive snaps among the linemen) and the coaches evidently feel comfortable with him in the lineup.
The concern with the 6-foot-6 Mitchell, listed at only 307 pounds, is that he lacks the girth to handle powerful pass rushers. His first assignment will be Ravens defensive end Calais Campbell, a six-time Pro Bowl selection.
"Obviously, he's a 15-year vet, so he's got some salt to him," Mitchell said. "Dude is big, long, strong, fast -- a freak athlete -- but it's nothing we can't handle, nothing we haven't seen on the field before. Obviously, he's a renowned guy, but he's just another dude."
"Max is much further along than we thought he'd be at this point," Saleh said. "We're very confident he'll be able to step in and do his job."
Brown had been a durable player in recent years for the Seattle Seahawks -- no missed games in 2020 and 2021 -- but he was a risky acquisition because of his age. The Jets brought him along slowly, allowing him several days of conditioning before clearing him to practice. He wound up participating in only a handful of practices and one preseason game before getting hurt.
"The guy moves around like he's 29, so he's got a lot of life left in his body," Saleh said. "You can always play the hindsight game, but with Duane there were no indicators."