Smith hasn't played a snap in the NFL since 2015 when he was suspended indefinitely for violating the league's substance-abuse and personal-conduct policies. He appeared in just nine games for the Raiders prior to the suspension, and he never played a down under the two-year contract he signed with the team prior to the 2016 season. He remains suspended by the NFL.
Smith was slated to become a free agent when the new league year started March 14.
On Sunday, San Francisco police named Smith a suspect in a domestic violence incident that happened Saturday night. The victim suffered non-life threatening injuries and Smith fled the scene prior to the police's arrival. Investigators from the SFPD Special Victims Unit want to interview Smith about the incident.
Smith, 28, has been involved in several off-field incidents since being selected by the 49ers in the first round of the 2011 NFL Draft. He tallied 33.5 sacks over his first two seasons with San Francisco and was released by the team in August 2015 hours after he was arrested on hit and run, DUI and vandalism charges.
He applied for reinstatement from his suspension in November 2016 before being the subject of a domestic violence investigation in February 2017.