Coach Pete Carroll said he will need surgery for leg and knee issues and will be placed on injured reserve.
"He needs to get work done on his knee," Carroll said. "He got caught in a situation, just got hit on the outside of his knee, and it got him. In unbelievable fashion, he finished the game. It was early enough, he fought through it the whole time. And this has just been such a difficult season for Mike. My heart goes out to him. He wants to be part of this thing so badly, but he doesn't get to this time around. We'll look forward to getting him back next time and keep him with us."
Kendricks started in Monday's 21-7 victory over the Minnesota Vikings in place of the injured K.J. Wright (knee) after serving an eight-game suspension stemming from his guilty plea to insider trading charges. Carroll said Wright is still weeks from playing.
"K.J. went through the walk-through today. I watched him run yesterday and he looks good. He's getting close. This will be an important week to just kind of work him back in and hopefully a couple weeks from now we'll get a chance to get him back."
Asked about Kendricks' broken tibia, Carroll said: "There's a little nick in there or something. There's a couple things that they're going to work on. It's not a terrible knee injury, but it's going to take a little bit. It's at least six-to-eight weeks kind of a situation. So that's where we're at."
Kendricks is scheduled to be sentenced in January. One source familiar with the situation said Kendricks could be facing 30 to 37 months in prison based on federal guidelines and the amount of money involved. It's possible that Kendricks' contrition and transparency will help him.
The Cleveland Browns released Kendricks after he was charged, and he signed with the Seahawks in September. The NFL originally suspended Kendricks indefinitely but announced an eight-game suspension after reviewing the matter.
He finishes his 2018 season with two sacks, 20 tackles and a pass defensed in four games with Seattle, including three starts.
He played his first six seasons with the Philadelphia Eagles but was released in May.
"I saw him on a handful of plays when he really had something to do," Carroll said of Kendricks' play. "I thought he was right where he was supposed to be a couple of times. He made some good tackles in the open field -- forced a screen beautifully. He's a really good football player. We're excited to have him out there. I think he makes us better."
Without Kendricks, the Seahawks will likely turn back to Austin Calitro, who has been part of the committee Seattle has used at weakside linebacker in Wright's absence. Rookie Shaquem Griffin started the season opener in that spot.
The Seahawks signed linebacker Emmanuel Ellerbee off their practice squad to fill the open roster spot, with Kendricks going on injured reserve.
Calitro, undrafted out of Vilanova in 2017, has started four games this season. His most recent start was two weeks ago against the 49ers, when he made a career-high 10 tackles.
Carroll said of Calitro stepping in this season: "He really has done it, and he's done it well for us. He played really good against these guys last time out. He's been able to be really consistent with his run fits, really don't have any problem with him playing at all. We were excited to play Mychal last week to give him a chance to get out there, but Calitro and him could easily have swapped in. So we feel like we have a guy that we've developed as a starter stepping up, and we're fortunate."
Carroll said receiver Doug Baldwin, who missed the Vikings game with a groin injury, is uncertain for Sunday. In a move that could be related to Baldwin's iffy status, Seattle signed receiver Damore'ea Stringfellow to its practice squad.
"He went through the walk-through today too. We'll see how he does this afternoon. We'll just go one day at a time with Doug, and never expecting anything other than he may pull off another one of these miracles to get back and play. His mind is set on doing that. We'll see how he makes it through the week. I can't tell you right now."
ESPN's Brady Henderson contributed to this report.