"Your time's going to come, and you've got to be accountable for when that opportunity comes," Leinart said Monday, after news of Schaub's injury was released. "They know that I work hard and I study hard and I'm prepared very well. We're going to take this and go game-by-game, and I don't think much is going to change."
Leinart has been named the starter when the Texans return from their bye week to face the Jacksonville Jaguars in Week 12. He talked openly during training camp about earning another starting job in the NFL, and now he has that chance -- at least temporarily -- just not under the circumstances he wanted.
"I'm bummed. My heart goes out for (Schaub)," Leinart said. "But he knows and everyone knows that in this profession, things happen, and the next guy has to step up. That's my job and my responsibility.
"That's what I've wanted for a long time, and that's what I've worked hard for every day and prepared for every day," Leinart added. "It's a great opportunity. I'm just excited about the chance."
"He's played in big football games in this league, he's played in big football games in college," Kubiak said. "Matt's been around it. The key is the whole team rallying around him, and playing well as a team. Matt doesn't have to go win a game, the team has to go win a game. We'll rally around him and get him ready to go."
Leinart will be aided by the NFL's third-ranked rushing offense as well as the expected return of star wide receiver Andre Johnson, who has missed the last six games with a hamstring injury.
Leinart, the 2004 Heisman Trophy winner for Southern California who was drafted 10th overall by Arizona in 2006, re-signed with the Texans during the offseason after not taking a snap in 2010. He turned down other offers to return to Houston because he was comfortable with Kubiak and his offensive system.
The Associated Press contributed to this report.