The Texans secondary suffered its third major injury on Sunday, losing Kayvon Webster early against the Dallas Cowboys. Webster, in his first game after a season-ending Achilles injury last year with the Los Angeles Rams, made the first stop of the game but left early in the first quarter with a quadriceps injury. He did not return.

"I don't know the final diagnosis on it," head coach Bill O'Brien said Monday. "I'll be able to tell you better on Wednesday when the injury report comes out whether he'll be day-to-day or a couple of weeks or whatever it is."

The Texans place Kevin Johnson on injured reserve after back-to-back concussions in the preseason and in Week 1 at New England. Aaron Colvin suffered an ankle injury at Indianapolis in Week 4 and could also miss the remainder of the season.

Kareem Jackson  switched to the safety position this year and has filled the gap at cornerback nicely. However, O'Brien has not decided if the nine-year veteran will return to his old position with all the recent injuries.

"I don't know yet," O'Brien said. "There's a lot of possibilities out there. You'd really like to try to keep him at safety, to be honest with you, because he's had a good year there, but he'll do whatever's best for the team. I know that."

The Texans currently have cornerback Johnson Bademosi, who mostly contributes on special teams, on the active roster and rookie Andre Chachere on the practice squad, but they could be looking to add depth to the secondary soon.

"We've got a lot of guys that are versatile guys back there," O'Brien said. "Obviously, we'll probably be looking at our practice squad, we'll be looking at guys that are on the street right now, but we'll figure it out."

The (2-3) Texans will host the (2-3) Buffalo Bills on Sunday. Kickoff is set for 12 noon CT on CBS and SportsRadio 610.