SAN FRANCISCO — Jim Harbaugh declined Monday to "rehash" the 49ers' decision to play Aldon Smith on Sunday, and the coach instead discussed how they'll forge ahead without their sack leader, who is on indefinite leave for treatment after his recent drunken-driving arrest.
"There's adversity. There's an opportunity to stare it in the face and whip it," Harbaugh said.
Smith reportedly was flying to a rehabilitation center Monday morning, according to ProFootballTalk.com. Harbaugh declined confirmation and said an official statement will be forthcoming, presumably from the 49ers or the league.
Smith is expected to bewas placed on a non-football-injury list. His timetable of returning is unknown, as is his destination for treatment.
The 49ers likely will use a committee of defenders to fill in for Smith, who played all 72 defensive snaps in their 27-7 loss to the Indianapolis Colts.
Smith was a part-time player in 2011, so look for defensive coordinator Vic Fangio to again shuffle players into that spot at right outside linebacker and right defensive end, depending on if it's a run or pass situation.
Three players stand out as likely temps in place of Smith.
-- Demarcus Dobbs: A third-year veteran, Dobbs is their top backup on the defensive front. Suspended for the opener because of his own alcohol- and marijuana-involved car accident, he's rotated in the past two games, typically spelling defensive tackles Justin Smith and Ray McDonald. He has no career sacks in 26 games.
-- Corey Lemonier: The rookie, third-round pick out of Auburn likely would be used strictly as a pass rusher. He hasn't had any snaps on defense, but 24 on special teams. He had two sacks in the exhibition season.
-- Dan Skuta: Base defense likely is where Skuta will be deployed. After four years with the Bengals, Skuta looked solid in the exhibition season and had three sacks. But he hasn't taken a defensive snap through three regular-season games (46 special-teams snaps).