HOUSTON -- Entering Week 7, the Houston Texans have the second-best passing defense in the NFL. But they don't have one of the league's healthiest secondaries.

Cornerback Kevin Johnson broke his foot on Sunday against the Colts, while Kareem Jackson (hamstring) and safety Quintin Demps (calf) are day-to-day for Houston. Veteran cornerback Johnathan Joseph has left two-straight games after suffering a concussion against the Minnesota Vikings in Week 5 and with a forearm injury against the Indianapolis Colts on Sunday. He said he is "fine" and hopes to play on Monday night in Denver.

With the injuries, the Texans have had to lean on cornerbacks A.J. Bouye and Robert Nelson. Nelson, who was promoted from the practice squad to the active roster last week, had an interception against the Colts. Joseph said he has tried to help the younger players make the transition.

"[I] just talk to guys constantly about whatever role they are going to be playing or just try to help them out, get them up to speed with the playbook or just a game plan," Joseph said.

Though the Broncos are ranked 25th in the NFL in receiving yards per game on offense, they have two good receivers in Demaryius Thomas and Emmanuel Sanders.

"[They're] quick guys," Bouye said. "Good with the ball in their hands. They run great routes. Like I said, we got to play with really great technique. We got to be disciplined."

Bouye said he has seen on the film that Broncos quarterback Trevor Siemian is "a good quarterback," and that the Texans' defense needs to come to play with good technique and continue to compete all game against Siemian.

"All you can do is just focus on you, focus on your technique, focus on your job and how you can help the team win," Bouye said. "That's what I'm trying to do. Just take care of my body and just stay in the game plan because whatever Coach (Bill O'Brien) needs me at, I just got to be ready for it."

But though the Texans' secondary is dealing with injuries, O'Brien said they cannot let that get in the way of making plays.

"Injuries happen," O'Brien said. "It's unfortunate when they happen to your best players, but they do and the next guys have to step up. We've done that in many regards. The guys who have been back up players have stepped up and made plays. Robert Nelson is a great example of that. Obviously up front, losing J.J. (Watt) and the way those guys are playing overall.

"There's some things they can do better, but those guys are stepping up and I think that's the key to this league."