Dockett signed a $7.25 million, two-year deal with the 49ers in March following his release by the Arizona Cardinals after 11 seasons with the team. He was not guaranteed any money and did not receive a signing bonus.
Dockett, 34, is now a free agent just a day before teams must cut their rosters down from 75 to 53.
The defensive tackle sustained an injury during a preseason game against the Broncos. Dockett posted a photo indicating that he had a cracked rib, though 49ers coach Jim Tomsula said it was actually a cartilage issue.
Dockett has not played in a regular season game since 2013. He missed the entire 2014 season with a torn right ACL, an injury he sustained during training camp that year.
- Xandria James