CHICAGO -- The Chicago Bears made Jason Campbell one of the highest-paid backup quarterbacks in the NFL for situations just like this.

They have to be hoping they won't need Campbell's services for an extended period after starter Jay Cutler was knocked out of Sunday night's game with a concussion on a vicious hit to the head/neck area from Houston linebacker Tim Dobbins.

As the Bears found out last season, life without Cutler isn't pretty.

Campbell, the former Raiders quarterback, was more in control than last year's bargain-basement backup, Caleb Hanie, who lost four straight games after Cutler was sidelined by a broken hand. But Campbell wasn't able to rally the Bears as the Texans (8-1) won 13-6, ending the Bears' six-game winning streak at soggy Soldier Field and dropping them to 7-2.

Only one Bears victory -- the opener against the Colts -- has come against a team with a winning record.

It's premature to determine if Cutler will be available for next Monday's game at San Francisco. The 49ers also could be without their starter, Alex Smith, who left in the first half of a tie with the Rams with a concussion. Both players must be cleared to return by an independent neurological consultant. Bears defensive end Shea McClellin also was knocked out with a concussion.

Cutler, who was 7 of 14 for 40 yards with two interceptions, was injured late in the second quarter when he stepped up in the pocket to throw to Devin Hester. Dobbins appeared to hit Cutler in the helmet, and referee Gene Steratore called it a hit above the shoulders. The 42-yard pass to Hester was erased, though, as officials ruled Cutler had crossed the line of scrimmage.

"It was good that he was out," Dobbins said. "You always want to take the quarterback out of the game. I hit him in his chest. I did not hit him in his head. Nowhere near."

Bears players disagreed.

"That was ridiculous," center Roberto Garza said. "You shouldn't hit players in the head."

Campbell, signed to a one-year, $3.5 million contract, made some plays, including a 45-yard pass to Brandon Marshall, but it's hard for a backup to come in cold. He finished 11 of 19 for 94 yards.

"I'll be more comfortable," Campbell said when asked if he will be better prepared next week if needed. "Just because tonight was my first reps of the season. I'll compete my butt off."

Arian Foster finished with 102 yards rushing for the Texans, who are tied with Atlanta for the NFL's best record after the Falcons lost to New Orleans.

"I think we showed them we can win any game, any situation, any time, any place, tough weather conditions, tough place on the road, a very good football team," defensive end J.J. Watt said. "We won, so say what you want."

The Associated Press contributed to this report.