Texans coach Gary Kubiak took the blame for the performance, but there was plenty to go around.
The offensive line was dominated by New York's defensive front. Foster, the NFL's leading rusher through the four games, was held to 25 yards on 11 carries. Schaub was sacked three times, lost a fumble and threw an interception. Johnson caught five passes, but was targeted 13 times.
The Texans (3-2) were held to a franchise-low 24 yards rushing. Kubiak said late Monday afternoon that he hadn't even looked ahead to Sunday's game against Kansas City (3-1), because he was still pouring over what went wrong against the Giants.
"They stopped pretty much everything we did," Kubiak said.
New York led 21-0 early in the second quarter, and the Texans had only run 13 plays for 28 yards by then. When Kubiak watched the replay, he picked out at least eight missed assignments by offensive linemen during that stretch.
"That has not been us at all," Kubiak said. "We have been somewhat consistent from that standpoint."
The Giants had 10 sacks in a 17-3 win over Chicago the previous week, but the Texans' offensive linemen blamed the breakdowns against New York on their own fundamental mistakes.
"When four guys are doing it right, and one guy doesn't, the play is not going to work out," right guard Antoine Caldwell said. "Everybody took their turn up front, not doing the right thing — technique-wise, assignment-wise. That's why it led to such a sloppy game."
The Texans came in leading the NFL in rushing (172 yards), but the Giants penetrated the line and prevented Foster from cutting back every time he touched the ball.
"They did do a good job in gap assignments," Caldwell said. "You've got to have a lot of extra-effort plays, not just covering guys up, but blowing people off the ball. We didn't have a lot of those, for whatever reason."
Kubiak virtually abandoned running plays after the Giants sprinted to the big early lead.
Schaub didn't fare much better with the passing game. He had at least three throws knocked down at the line of scrimmage and completed only 16 of 34 passes. He didn't throw a touchdown pass for the first time in 12 games.
"He didn't have a lot of help," Kubiak said. "He didn't have a lot of help up front, we dropped some balls. We need to do a better job protecting him, we need to run some better routes. He'd be the first one to tell you he wasn't good enough for us to win, but there's a lot of people involved in that."
Johnson seemed a step slow as he played through a sprained right ankle that's nagged him for three weeks. Tight end Owen Daniels had three catches, and no other wide receiver had more than two.
"It was bad. We didn't play good at all," said Kevin Walter, who had two catches for 24 yards. "We have a lot of weapons, but we have to execute our game plan. It's always about execution."
The Texans showed efficient balance in their first two games. Foster rushed for 231 yards in the opening win over Indianapolis, and Schaub threw for 497 yards in Houston's win over Washington the following week.
Dallas accomplished many of the same things that the Giants did on Sunday, pressuring Schaub (four sacks) and shutting down Johnson (four catches, 64 yards).
The Texans rushed for 249 yards against Oakland before Sunday's dismal outing.
"We've played some very good games and a couple poor ones in big spurts," Kubiak said. "Very good in spurts and very bad in spurts. So we're trying to find some consistency there as a football team. That's the key to being a great football team. That's the hardest thing in this league to find and we're searching for that. Obviously, we've got a long way to go to get that done, but somehow we've got to find some consistency in what we're doing."
Kubiak said Foster hurt his knee on Sunday, but ran on Monday and should be ready for this week's game. Kubiak said Johnson's ankle "came out of the game fine."