Kendricks had been appealing the suspension. He is not scheduled to be sentenced until Jan. 24, when, based on federal guidelines, he could be facing 30 to 37 months in prison.
The Seahawks expected to receive word from the NFL by Tuesday on whether Kendricks would be available for Sunday's game at home against the unbeaten Los Angeles Rams.
The 28-year-old Kendricks has been filling in for K.J. Wright at weakside linebacker. Wright has yet to play this season following arthroscopic knee surgery he had in late August, and coach Pete Carroll said Monday that it could be a couple more weeks until he's ready. Rookie Shaquem Griffin is an in-house option at the weakside spot until Wright returns.
The Cleveland Browns, who signed Kendricks as a free agent during the offseason, released him in August after his involvement in insider trading surfaced.
Seattle signed Kendricks while middle linebacker Bobby Wagner was hurt, which left the team without Wagner and Wright for its loss against Chicago on Sept. 17. Carroll said at the time of the signing that the Seahawks had done "a lot of homework" on Kendricks' situation.
"It happened four and a half years ago, so it's a story that's been worked on for a long time," Carroll said. "There's a lot of good information. We've come to learn who he is and what he's all about and how remorseful he was and how he admitted to his mistake a long time ago -- he paid the money back, he did all of the right things along the way. The process continues, but we just checked everything we could possibly check out, and he's a guy that deserves a second chance."
Kendricks recorded 15 tackles and a pair of sacks over his three games with Seattle. The team signed him to a one-year deal worth $743,529, which is the prorated amount of a $790,000 minimum salary. Kendricks did not receive a signing bonus.
"I think he's really a good ballplayer," Carroll said Monday. "Gosh, he's instinctive and fast and tough and smart, and he's got a good attitude. He's got a good toughness about him that, if something's not going right, he's determined to fix it and get it right. He's got a real good sense about him. I think he's really good. We'll miss him if he doesn't get to play with us, but while we have him, we're going to continue to work him."
Griffin, who became the first player with one hand to be drafted in the NFL's modern era when Seattle chose him in the fifth round, started in Seattle's season-opening loss to the Denver Broncos.
In addition to losing Kendricks to suspension Tuesday, the Seahawks also placed safety Earl Thomas and rookie tight end Will Dissly on injured reserve. Both are expected to miss the remainder of the season; Thomas fractured his tibia and Dissly injured his patellar tendon in Seattle's victory over the Arizona Cardinals on Sunday.
The moves leave Seattle with three open spots on its 53-man roster.
Safety T.J. Green posted a note on Twitter Tuesday night saying he had joined the Seahawks.
Green, a second-round pick out of Clemson in 2016, was released by the Indianapolis Colts with an injury settlement on Sept. 6.
He injured his hamstring during the Colts' third preseason game against the 49ers. In 31 games, including 11 starts, with the Colts, Green had 87 tackles with three passes defensed.