Smith played Sunday and had five tackles just two days after he was arrested and jailed Friday morning on suspicion of DUI and marijuana possession. Smith apologized after the 27-7 home loss to the Colts, and now his team moves forward without him heading to St. Louis on Thursday.
"We're very supportive of Aldon as we are of all of our players, all of our coaches, our personnel. Always support it in house," coach Jim Harbaugh said. "We've hashed through it, now we're taking steps and Aldon's taking steps. We support him in that."
San Francisco didn't immediately announce a corresponding roster move.
"We have a pretty good idea what we're going to do and we'll make that announcement," Harbaugh said. Smith had previously been arrested on suspicion of DUI in January 2012 in Miami shortly after the 49ers lost in the NFC championship game. He is expected to remain in the Bay Area for treatment.
He could face a suspension from the NFL either later this season or next season, and it is likely given he has had more than one infraction. The NFL would let the legal process play itself out first. Harbaugh said Dan Skuta, Ahmad Brooks and Corey Lemonier will help fill the void left by Smith, who had a franchise-best 191/2 sacks last season.Demarcus Dobbs, who was suspended for Week 1 for his own arrest on suspicion of DUI and marijuana possession from last season, also could be in the mix for some packages.
"I have confidence in those guys and know they'll do a good job," Harbaugh said. "Go with the guys we've got."
Smith, selected seventh overall in the 2011 draft out of Missouri, turns 24 on Wednesday.
Harbaugh and general manager Trent Baalke ultimately decided to let Smith play before he entered rehab.
"Aldon Smith is taking a leave of absence to address a personal matter," Baalke said in a statement. "The 49ers organization both respects and supports Aldon's decision and commends him for taking responsibility for his actions. The long-term well-being of our players is paramount and we will stand by Aldon as he works toward addressing this issue. Due to the private nature of the matter, we will have no further comment."
His 49ers teammates were trying their best not to let the situation become a distraction. San Francisco (1-2) has a quick turnaround to face division foe St. Louis on the road Thursday night.
"Coach decided to let him play, and he was out there and made some plays," safety Donte Whitner said. "I don't think guys were out there thinking about Aldon being arrested."
Earlier this month, Smith and former teammate Delanie Walker were named in a lawsuit filed in Santa Clara County Superior Court by a Northern California man who said he was shot at a party at Smith's house on June 29, 2012.
The players charged a $10 admission and $5 per drink, the lawsuit said. Smith and now-Titans tight end Walker, 29 were allegedly intoxicated on Smith's balcony when they fired gunshots in the air while trying to end the party, the lawsuit said.
Before the 2012 home opener last September, Smith was the passenger in a car during an accident in Santa Clara County in which the driver swerved to avoid hitting a deer. Smith sustained a cut beneath his right eyebrow. He apologized and insisted he had grown up.
Asked about Smith on Monday at Titans headquarters, Walker said he is getting more attention because of his status as one of the best in the NFL at his position.
"I pray for him because he is a good kid," Walker said. "He's just making some bad choices now."
Notes: CB Nnamdi Asomugha (leg) and LB Patrick Willis (groin) were getting MRI exams Monday, while Harbaugh said TE Vernon Davis was being evaluated after he missed Sunday's game with a hamstring injury. ... WR Jon Baldwin, acquired from Kansas City in the trade that sent WR A.J. Jenkins to the Chiefs last month, could be active for the first time Thursday as the 49ers look for more from their receiving corps. They had 13 total catches Sunday. "That's possible," Harbaugh said. "He's doing a good job, had a real good week of practice last week."
Around the league
Cardinals • Safety Rashad Johnson lost more than a football game in New Orleans. The tip of the middle finger on his left hand departed there, too. Johnson displayed the reduced digit to reporters when the team gathered in Florida, where it will practice in preparation for next Sunday's game against Tampa Bay. Johnson removed his glove after a tackle and found the top of his finger was still in the glove, which was drenched in blood. Now the index finger and middle finger are about the same length.
Johnson joked that the finger "probably wouldn't have been used for anything good anyway." Doctors shaved down the damaged finger and Johnson says he might be able to play next Sunday.
Packers • Green Bay released receiver and return man Jeremy Ross on Monday, a day after the second-year player muffed a kickoff that set up a touchdown in the wild 34-30 loss to the Bengals BenJarvus Green-Ellis ran for a 2-yard score to give Cincinnati a 14-0 lead on the play after Ross muffed the kickoff early in the first quarter.
Bengals • Cornerback Adam "Pacman" Jones was accused by police of making offensive comments while drunk during a traffic stop early Monday and was given a disorderly conduct citation. The driver was cited for drunken driving while Jones was cited for disorderly conduct. Both charges are misdemeanors.
Jaguars • Quarterback Blaine Gabbert, who missed the last two games after slicing open the back of his throwing hand, will start Sunday against the Indianapolis Colts, replacing Chad Henne.
Cardinals • Coach Bruce Arians says starting outside linebackers Sam Acho (broken leg) and Lorenzo Alexander (foot) are out for the season with injuries sustained in Sunday's loss to New Orleans.
Thursday, Sept. 26
San Francisco at St. Louis, 6:25 p.m.
Sunday, Sept. 29
N.Y. Giants at Kansas City, 11 a.m.
Seattle at Houston, 11 a.m.
Baltimore at Buffalo, 11 a.m.
Arizona at Tampa Bay, 11 a.m.
Indianapolis at Jacksonville, 11 a.m.
Cincinnati at Cleveland, 11 a.m.
Chicago at Detroit, 11 a.m.
Pittsburgh vs. Minnesota at London, 11 a.m.
N.Y. Jets at Tennessee, 2:05 p.m.
Washington at Oakland, 2:25 p.m.
Dallas at San Diego, 2:25 p.m.
Philadelphia at Denver, 2;25 p.m.
New England at Atlanta, 6:30 p.m.
Open: Carolina, Green Bay
Monday, Sept. 30
Miami at New Orleans, 6:40 p.m.