The NFL has suspended the heralded pass rusher for a full year for violating the NFL Policy and Program for Substances of Abuse.
Smith was involved in an August incident where he was charged with hit and run, DUI and vandalism. The arrest prompted Smith's ouster from the 49ers after four seasons.
Smith isn't guaranteed reinstatement into the league. He has to apply, and will first be eligible around mid-November next year. Smith's contract will not toll, so he will be an unrestricted free agent in 2016, NFL Media's Albert Breer reported.
"First, I want to thank the Raiders, my teammates, the fans, our coaches and our owner for supporting me throughout all of this," Smith said in a statement released by the team.
"I am taking this time to work on myself and become the man I need to be, my team and organization needs me to be, and I know I can be. I had lost my love for the game and it led me to some poor choices, but I am thankful to the Raider organization for believing in me this season and will continue to better myself and grow from my experiences. I look forward to rejoining the team next year."
The setback is a huge one for an Oakland team that has come leaps and bounds in 2015 under new head coach Jack Del Rio. Recently, general manager Reggie McKenzie said Smith was in the team's plans long term. The team reaffirmed as much in a statement released late Tuesday:
"Aldon has been a positive addition to the Raiders. He remains prominently in our long term plans and we will continue to support this member of our family as he gets the help that he needs."
Oakland had to anticipate an eventual suspension, especially given that this was Smith's third arrest for DUI. He was signed to an incentive-laden $8 million deal on the same day he was arraigned for his latest incident.
In all, the Raiders got 530 snaps out of Smith, who provided Del Rio with one of the most potent pass rushing duos in the NFL. Between Smith and budding star Khalil Mack, they combined for 62 hurries, nine sacks and eight quarterback hits. With games against the Lions, Titans and Chiefs ahead, the club could very well be 7-5 heading into the final stretch of the season.
Maintaining that pace will be difficult without Smith, though. The defensive line was already reeling in the wake of Justin Tuck's season-ending injury and unless they can get an other-worldly performance from the likes of Ray-Ray Armstrong and Benson Mayowa, there will likely be some reorganization needed up front.
The far more interesting part of this story will be whether or not the Raiders keep Smith long term. They have some time to think about it, but given his strong performance in early 2015 and the fact that he's been relatively quiet since his latest arrest, interest for the pass rusher's services should be high once his suspension is up. Certain troubled players are quick to be walled off from the NFL, but when you register more sacks in the first two years of your career than any other player in NFL history (33.5), doors tend to keep opening up.
This likely isn't the last we've seen of Smith. The only question will be where we see him next.