Locker Room Buzz: San Francisco 49ers

Observed in the locker room after the San Francisco 49ers' 34-3 win over the Houston Texans Sunday night:

McDonald worried: Defensive tackle Ray McDonald said he is concerned about a right bicep injury. McDonald said he felt a sting when he was injured. He has a MRI scheduled for Monday. It would hurt the 49ers if he misses extensive time.

Staying calm: Defensive players said veterans kept the sideline calm after Tramaine Brock returned a Matt Schaub interception 18 yards for a touchdown on the first drive of the game. Leaders made sure younger players knew there was still a lot of football left to play.

Shy star: Brock reluctantly spoke to a throng of media members after the game. He’s been camera shy since training camp. But now that he has supplanted Nnamdi Asomugha as the No. 3 cornerback, Brock may have to get used to the attention.

Deep defense: Players were boasting the 49ers defense being deep. Even with injured players this defense has been dominant the past two weeks, allowing a combined 14 points.