Smith, who re-signed with the Bengals for three years, $18 million in April, has missed all of the team's offseason workouts and didn't report Tuesday for the start of minicamp. Lewis said Smith would not attend any of the team's minicamp this week.
Lewis called it a "minor distraction" and said it's not related to his January arrest for possessing a gun at the Atlanta airport.
"He's really dealing with something that he has to get through," Lewis said. "We'd hope he'd be here to pick up on some of the things that we felt like were good to work on this point of the year. But he's got some personal things he's dealing with. Obviously, there are certain things that come with not being here for three days. It's unfortunate for him but that's just the way it is. Once we get through a week of training camp, everything will be good."
When Smith signed his contract on the second day of the draft, he said he weighed 335 pounds and reporters noted that the former first-round pick didn't appear to be out of shape. During the offseason, he has been training at Warehouse Performance Institute in Birmingham, Ala.
"I don't worry about that anymore," Lewis said of Smith's conditioning. "That's the one thing that Andre has taken good steps and made huge strides in personally from his own part for wanting to be a good player. He knows that part of it. From what I can see distance-wise, we're in pretty good shape."
Backup Anthony Collins will fill in for Smith at right tackle.
"He'll be prepared and he's hopefully doing the things he needs to do. When it's time to be with us, he'll be ready," offensive tackle Andrew Whitworth said. "We don't need to worry about that. We need to worry about what we have here and how we can go forward and get prepared and use these three days as an opportunity to take another step in the right direction."
The Bengals can fine Smith up to $66,150 for missing the three-day minicamp. Smith will also not receive the $100,000 workout bonus from his contract.
"There have to be ramifications from this," Lewis said.