Otah has been struggling with back and knee issues stemming from two prior knee surgeries. The Panthers decided to shut him down for the season to give him time to rest and fully recover, sensing he wasn't getting any better. He missed last week's game against Atlanta because of back problems.
Panthers general manager Marty Hurney said Wednesday Otah will not need surgery.
"I think we want to make sure that we give him time to strengthen that knee as much as it can be," Hurney said.
By the end of this season, Otah will have missed 35 games due to injuries while starting just 29.
Undrafted rookie Byron Bell, who has started twice this season in place of Otah at right tackle, is expected to start Sunday against the Washington Redskins. If Bell struggles, the Panthers could move left guard Travelle Wharton out to right tackle.
The team has added veteran offensive lineman Reggie Wells to the roster.
"Knee injuries, every time they're operated on, they're significant," Hurney said. "It's just getting that knee to the strength it needs to be and to not cause other problems and to get it strong as it can."
Weight issues may have contributed to Otah's back and knee problems. He reported to training camp at 355 pounds, about 25 pounds more than his listed weight in the media guide.
Rivera said Otah got down to 338 pounds with the help of the team's conditioning staff. He said players not being allowed to workout with team trainers this offseason because of the NFL lockout hurt Otah's chances of getting back healthy this year.
"It was disappointing," Rivera said of the decision. "It started with the back and then as things progressed the knee started bothering him. This to me speaks the importance of having offseason programs and having a guy around where he can rehabilitate and get ready to play."
Otah was unavailable for comment.
His problems first began in December of 2009 when he tore the meniscus in his left knee. He had surgery and was placed on injured reserve, missing the final three games.
He was expected to be back at full strength in 2010, but a minor arthroscopic knee operation during training camp wound up keeping him out all of last year. Otah participated in most of training camp this year and started four games, but conditioning issues prompted the Panthers to replace him at various points during games with Bell.
Otah's contract runs through the 2012 season. He's due to make slightly more than $1 million next season.
Hurney said he believes Otah will be back.
"We're confident and I think he's confident that he can work and get it stronger and the future will be bright," Hurney said.
Panthers quarterback Cam Newton said he's been impressed with Bell, saying "I'm on his bandwagon, so to speak."
"Everybody knows talented Jeff was and that injury is going to affect the team but at the same time we can't mourn over that," Newton said. "I think Byron knows that. He has a lot of confidence in himself. He has some games under his belt so everybody knows what he's capable of doing. Everybody expects there won't be any hiccups."
Otah becomes the fifth starter the Panthers have lost to a season-ending injury this year, joining linebackers Jon Beason and Thomas Davis, defensive tackle Ron Edwards, wide receiver David Gettis and guard Geoff Schwartz on injured reserve.
Rivera said Jason Phillips will start in place of Jason Williams this Sunday against Washington at outside linebacker and added the team may mix up its defensive line rotation after allowing Michael Turner to rush for 139 yards and two touchdowns in Sunday's 31-17 loss to the Atlanta Falcons. ... Rookie cornerback Brandon Hogan practiced Wednesday for the first time with the Panthers. They have three weeks to decide whether or not to activate Hogan from the physically unable to perform (PUP) list. Hogan tore his ACL last December while playing for West Virginia. ... Tight end Greg Olsen was held out of practice with a turf toe injury, but is expected to return to work Thursday, Rivera said. Also, linebacker Thomas Williams and safety Jordan Pugh were held out with concussions, while linebacker Omar Gaither remains sidelined with a sprained MCL in his knee.