Smith was arrested under suspicion of DUI last week following a single-car accident. He played in Sunday's game against Indianapolis, but decided to take a voluntary leave of absence following the game. On Sunday, Ian Rapoport of NFL Network reported the 49ers planned to place Smith on the non-football injury list once he registered for a treatment facility.
In a statement released by the team, general manager Trent Baalke said Smith was taking the leave to address a personal matter and the organization supported his decision. Smith said the break was to address his health.
"I am taking a leave of absence to address my health," Smith said in the release. "I am sorry that I have affected my team, my family and the organization. I will do everything in my power to handle this situation the best way possible. I appreciate the support of the 49ers and our fans."
By placing Smith on the NFI list while he is away, the team is not required to pay him his salary. While on the NFI list, Smith will not count towards the 53-man active roster. The move won't preclude him from returning this season as San Francisco would just need to clear a roster spot in order to activate Smith following his leave of absence.