Smith, a projected starter at nickel back, was arrested Sunday morning and charged with DUI. The sophomore was at practice Tuesday for the top-ranked Crimson Tide, and Saban said Smith has some "in-house" things to do in order to return in time for the Sept. 14 game against Texas A&M.
"We've never had an issue with Geno," the coach said. "He's an excellent person. He's never been in trouble before, never been in my office for anything. But I think this is something that everybody should learn from. When you make a bad choice, sometimes the consequences of that choice can really have a negative effect.
"Some of these guys don't have enough foresight to understand cause and effect, but Geno has been a really good person in the program and he just made a bad choice, a bad decision. Made several of them. Now, he's got consequences for it, and we're not going to have any other comment about that."
Smith played in all 13 games as a freshman during last season's national championship run, and his role on the nation's top defense increased late in the year.
Receiver Kevin Norwood said he was "really shocked" by Smith's arrest.
"I don't want to say anything negative about him because he really is a great guy and I've never really heard anything negative about him," Norwood said. "When I heard, I was like, 'Wow', but he knows it's a lesson learned and he's got to learn from it pretty much."
Starting middle linebacker Trey DePriest also returned Tuesday after Saban suspended him last week for violating team rules, saying the suspension would be a short one.
Saban said DePriest would have to work his way back up the depth chart.
Linebacker C.J. Mosley said both players stood up before the team at a players meeting and apologized.
"We want zero distractions when the season comes, so hopefully he (Smith) learned his lesson and everybody else learned from that, too," Mosley said.