Miami announced the move on Tuesday. The Dolphins waived linebacker Justin March-Lillard in a corresponding move.
The 10-year NFL veteran joined the Dolphins on March 10 as an unrestricted free agent, signing a two-year, $12 million contract.
Timmons went missing a day before the Dolphins Week 2 win against the Los Angeles Chargers. He was found this next day and suspended by the team indefinitely on Sept. 19.
The 31-year-old defender also missed the team's second game on Sunday, a 20-6 Week 3 loss to the New York Jets.
Timmons ranks No. 3 in the NFL with 893 combined tackles since 2009. His streak of 101 consecutive starts came to an end in the Dolphins' season-opener.
March-Lillard joined the Dolphins after being claimed off of waivers on Sept. 3 from the Kansas City Chiefs. He had one assisted tackle on special teams in two games this season for the Dolphins. March-Lillard had 22 combined tackles in five games for the Chiefs last season. He entered the NFL in 2015 as an undrafted college free agent out of Akron.
Dolphins Live: Lawrence Timmons meets with the media. https://t.co/tkS3lZcmx9— Miami Dolphins (@MiamiDolphins) May 23, 2017
Dolphins coach Adam Gase said Thursday that he had not yet made a decision about when Timmons' suspension would end.
"I haven't made any decision," Gase told reporters. "I'm going one day at a time right now. I know there are steps that are being made with what's going on with him. [Executive vice president of football operations] Mike [Tannenbaum] is really taking the lead on that. I'm getting updates as we go. My biggest thing is I'm trying to focus. My sole focus is this week, guys that are here, focusing on the Jets, making sure that we're ready to go. These weeks come quick. There's more downtime when you get to that Friday, Saturday to where if I needed to look at something, research something, talk to somebody, it's better for me to do towards the end of the week than right now."
Gase also told reporters on Monday that he didn't have an update on the linebacker's status.
Miami's current depth chart includes Kiko Alonso, Stephone Anthony, Mike Hull, Rey Maualuga, Chase Allen and Timmons at linebacker. The Dolphins added Anthony via trade on Sept. 20, while shipping a 2018 draft pick to the Saints.