HOUSTON (AP) -- Super Bowl or bust has turned into bust for the Houston Texans.
Six games into the season, the year has quickly soured for a supposed championship contender. The Texans have lost four in a row and the unbeaten Kansas City Chiefs await.
Houston's biggest problem has been turnovers. The Texans are allowing the fewest yards in the NFL (252.8), and are gaining the seventh most (395.7). But they have 12 more turnovers than their opponents, second most in the NFL.
''Turnovers get you beat in this league and they're getting us beat on a consistent basis,'' coach Gary Kubiak said.
And the status of quarterback Matt Schaub - battered by criticism - is unclear because of an injury he sustained on a sack in the third quarter Sunday.
''Obviously he's very sore and beat up on the leg, ankle - everywhere,'' Kubiak said. ''So obviously we'll have to see where he's at - probably got a little bit lucky there.''
Kubiak said Schaub was receiving injections for his injury Monday afternoon. Schaub left after Sunday's game before talking to reporters so he could have tests done.
Schaub didn't have a turnover Sunday after throwing six interceptions, three of them returned for touchdowns in the past three games.
''I thought he stepped up and improved,'' Kubiak said. ''You can always play better, but I thought he was doing things much better.''
Kubiak said he'll prepare both T.J. Yates and Case Keenum this week in case Schaub can't play.
Fans have been clamoring for Schaub to be benched in favor of Yates as he struggled. But when Yates got a chance to play Sunday, things didn't go well. He threw two interceptions, the first of which was returned 98 yards for a touchdown.
Whoever is at quarterback for Houston on Sunday will face a Kansas City defense allowing the NFL's fewest points a game at just 10.8. The Chiefs also lead the NFL in sacks with 31 this season.
''They're exceptional and even better at home with the crowd and what they've got going there,'' Kubiak said of the Chiefs. ''They've been pretty special.''
The Texans have already lost the same number of games as in the entire 2012 regular season, which has some wondering if Kubiak's job is in jeopardy. He said he has plenty of other things to concern himself with and isn't thinking about that.
''I think I've probably been asked that a few times in my eight years,'' he said. ''I've got a lot of people to worry about, a lot of players, a lot of coaches. I think it would be very selfish if I worried about myself, so no, I do not.''
Another problem for Houston has been penalties. The Texans had 95 yards of penalties on Sunday and have 46 penalties for 459 yards this season. Kubiak is trying everything to get the Texans to clean up their play.
''You've just got to emphasize in every possible way what you can on the practice field, in the meeting room,'' he said. ''That's about all you can do. Just paying as much attention to it as you possibly can.''
Also injured in Sunday's loss to St. Louis was safety Danieal Manning, who Kubiak said has a ''significant knee injury.'' He said they are still evaluating the injury.
Shiloh Keo will fill in for Manning. Keo was a fifth-round draft pick in 2011 who spent time on the practice squad that year before appearing in 14 games last season. Kubiak also said cornerback Brandon Harris could move to safety if they need more help.
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