This marks the Ravens' first game without middle linebacker Ray Lewis because of a torn right triceps tendon suffered against the Dallas Cowboys.
The Houston Texans have already endured a similar damaging blow, losing star linebacker Brian Cushing to a torn left anterior cruciate ligament on a low block by New York Jets offensive guard Matt Slauson.
During their first game without Cushing last week, the Texans lost, 42-24, to the Green Bay Packers as quarterback Aaron Rodgers delivered six touchdown passes.
"Obviously, Cushing, he's such a huge presence," Ravens Pro Bowl running back Ray Rice said. "I feel like he anchored that defense. He got everything rolling. He covered just as good as he rushed. I'm good friends with him, and I wish him a speedy recovery."
The Texans have Bradie James and Tim Dobbins as their starting inside linebackers in a formidable 3-4 defense engineered by veteran defensive coordinator Wade Phillips.
Cushing had 43 tackles, a forced fumble and an interception in the first five games.
The former USC standout ranks fourth on the Texans' all-time tackles list with 366 tackles in four NFL seasons. He also has seven interceptions and six forced fumbles.
"The other linebackers, no knock on them, they're filling in great, but you can't think you can replace a guy like Cushing right away," Rice said. "Because what Wade Phillips has done with that defense is essentially built around him doing what he had to do."
The Packers piled up 25 first downs and 427 yards of total offense against the Texans last week.
"Everybody has them games where a team just has their number," Rice said. "Green Bay came in with a great game plan and executed it. That's not to say they won't show up ready to play on Sunday."
This is a pivotal game Sunday considering that it may determine home-field advantage for the AFC playoffs.
"We know where we're at in the AFC," Rice said. "This game basically puts us at the top and everybody else two or three games behind."
Formulated by general manager Rick Smith, the Texans' front seven is headlined by dominant defensive lineman J.J. Watt, who leads the NFL with 9 1/2 sacks to go with 48 tackles, 16 tackles for losses, 15 quarterback hits, eight pass deflections and two fumble recoveries.
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The Texans also have athletic, aggressive personnel in outside linebackers Connor Barwin and Brooks Reed and Pro Bowl defensive end Antonio Smith.
"Their front seven is cream of the crop in the league," Rice said. "I knew that last year after our playoff game, what they were building. And that's something that they've been building over the years. They have everything over there. Those guys will be ready to play on Sunday."
The Ravens (5-1) have never lost to the Texans (5-1), winning all six of their previous meetings, including the AFC divisional playoff game in Baltimore last year.
However, the Texans are favored to win Sunday's game at Reliant Stadium.
"It's sort of like that Pittsburgh Steelers kind of game," Rice said. "The Houston Texans, man, are an up and coming team. They've arrived. It's the best start in franchise history and they've earned it. One thing about them, they've earned the respect of the rest of the NFL.
"Nobody is looking at the Houston Texans anymore on their schedule and saying, 'Oh shoot, we've got an easy game. You look at the Houston Texans and you know you're in for a fight."