Lewis won't play; third QB won't travel

Coach Mike Singletary met with the media, and here are the issues he addressed: --Safety Michael Lewis will not suit up for the game. He sustained his third concussion since mid-August on Oct. 11, and the 49ers are taking a conservative approach with him. "It's a matter of continuing to talk to the doctors and talk to the trainers and making a decision of what's best for him," Singletary said. --Mark Roman, the team's third safety, will make his first start of the season. --Third QB Nate Davis missed his second day with an "illness" and will probably not make the trip to Houston, Singletary said. When asked if Davis has the flu, Singletary said, "It could be, but I'm not sure. I didn't go that far. I just know it's some kind of cold." **(UPDATE: A 49ers spokesman said Davis does not have swine flu.)** --Singletary was asked about the quarterback situation. "I wanted to go with the guy who gave us the best cha...