Houston scored at least 30 points in four victories this season, but the Texans trailed, 17-3, after a dismal first half in Indy.
Houston coach Gary Kubiak said Tuesday that he was puzzled by the usually reliable offense's uncharacteristic mistakes.
"We didn't line up well a couple of times early in the game, we had trouble in the huddle, trouble with some splits, we dropped the football," Kubiak said. "Those are things that we're pretty automatic (at doing). We've got a group of guys who've been doing it together for a long time, and to all of a sudden get in that environment and not be ourselves there for a period of time, it's kind of confusing."
Houston plays Sunday against San Diego (3-5) and the league's top-ranked defense.
"Last year, we protected the quarterback pretty darn well," Kubiak said. "This year, we've protected in spurts. We've got too many sacks. We need to cut those down. The best way to cut them down is how you run the football and how you control the line of scrimmage."
Foster carried only 15 times for 102 yards -- including a 33-yard run -- in Monday's game. Kubiak said Houston's inability to convert third downs forced him away from using Foster.
"It would've happened," Kubiak said. "Do I wish he would've carried the ball 35 times? Yeah, we would probably be in a totally different football game if that happens. It happened due to the fact that we were 0 for 6 in the first half on third downs. We couldn't stay on the field."
And that meant more snaps for the Texans' defense, which came in ranked last in the league. Manning threw for 433 yards and three touchdowns in the opener, so Kubiak was pleased that his defense limited the four-time MVP to 268 yards passing and two touchdowns in the second meeting.
"For Peyton to throw for what he threw for," Kubiak said, "we've got to feel good on the defensive side of the ball when you look at the numbers."
Kubiak also said he saw more improvement from rookie cornerback Kareem Jackson, who has taken much of the criticism for the Texans' worst-ranked pass defense.
Houston has been outscored, 109-50, in the first half this season, another issue that has Kubiak scratching his head.
"We've actually moved that ball early in football games the first drive, but we have not been effective scoring points," Kubiak said. "We've had a bunch of sacks in first drives of games, and actually some of our biggest penalties offensively have been in the first drives of games.
"I'm looking hard at that and come up with a reason or try to see what we may do differently or take a look at some of those things as we move forward. But we have been poor early in games."
Copyright 2010 by The Associated Press