49ers' Smith to seek treatment

The San Francisco 49ers announced after Sunday's loss to the Indianapolis Colts that outside linebacker Aldon Smith will be taking an indefinite leave of absence from the team to seek help for a substance-abuse problem.

Smith was arrested on charges of driving under the influence and possession of marijuana after crashing his car in San Jose's Silver Creek district early Friday morning, though he played in Sunday's 27-7 defeat to the Colts and recorded five tackles.

49ers CEO Jed York said following the game that Smith will not play in Thursday's matchup at St. Louis and there is no timetable for his return.

"We are very fortunate that nobody got hurt, Aldon included, and anybody else," said York in reguards to Friday's incident. "We want to make sure that Aldon is never in a position like this again."

Smith has been involved in a few off-field issues during his three-year NFL career. The All-Pro pass rusher was arrested on a previous 2012 charge in Miami in January of 2012, and more recently was named in two lawsuits stemming from a house party he hosted in June of last year. He was reportedly stabbed at the party.

"First off, I wanted to apologize to the team, the organization, my family, everybody that I let down," said Smith after Sunday's game. "I also wanted to let it be known that this is a problem. It's something I will get fixed, and I will do everything in my power to make sure that this never happens again."

York also admitted that both he and Niners head coach Jim Harbaugh made the decision to allow Smith to play in Sunday's contest.

On the field, Smith has been one of the NFL's premier pass rushers since being taken by San Francisco with the seventh overall pick of the 2011 draft. He notched 14 sacks during his rookie season, then ranked second in the league with 19 1/2 sacks last year while helping the 49ers to an appearance in Super Bowl XLVII.