Starting nose guard Ma'ake Kemoeatu was scratched due to a sprained knee that bothered him all week during practice.
"It just didn't look right," Harbaugh said. "He had fought through it all week, but he wasn't moving as well as we'd like for him to."
Nose guard Terrence Cody started in place of Kemoeatu, who took away Cody's spot during the preseason. Cody finished with two tackles.
"Yeah, I was a little banged-up," Kemoeatu said. "I'll give it a break and get ready during the bye week. I'll be back after that."
Reed downplays rib injury
Free safety Ed Reed landed awkwardly on top of a Texans player's foot in the fourth quarter, suffering a rib contusion.
However, the former NFL Defensive Player of the Year returned to play. Afterward, Reed downplayed the severity of the injury.
"It was my rib and kidney, I think they said I took a cleat," Reed said. "It felt like I fell on a shoe or something. It's just really sore right now. It hurt like heck when I was out there.
"I just hoped nothing was broken and I didn't feel like anything was broken. It just kind of cut my wind a little bit, but I'll be all right."
Rookie kicker Justin Tucker booted a 51-yard field goal in the first quarter, setting a franchise single-season record for the most field goals 50 yards and above. ... Besides Kemoeatu, the Ravens deactivated rookie cornerback Asa Jackson, running back Bobby Rainey, offensive tackle Ramon Harewood (migraines), offensive tackle Jah Reid (strained right calf), wide receiver Deonte Thompson and tight end Billy Bajema. ... Inside linebacker Dannell Ellerbe had a game-high dozen tackles as he started at weakside inside linebacker opposite middle linebacker Jameel McClain. McClain had four tackles in his first game starting at injured middle linebacker Ray Lewis' vacated spot. "Yeah, it's strange," Ellerbe said. "You expect Ray Lewis to be around. He's always been around. It's weird, but we got to step up. We can't do this again."