In past seasons, an injury to their All-Pro receiver would’ve doomed the Houston Texans.

That was before they had Arian Foster.

Foster rushed for 155 yards and scored the go-ahead touchdown after Johnson left with a hamstring injury, leading the Texans to a 17-10 win over the Pittsburgh Steelers yesterday.

“I go into every contest thinking that I’m the go-to guy,’’ Foster said. “When the flow of the game starts going, we need certain things, and you’ve got to be there for your team.’’

Johnson was back on the sideline late to watch Houston (3-1) finish off Ben Roethlisberger and the injury-plagued Steelers (2-2). Houston coach Gary Kubiak said Johnson would undergo tests last night.

“Now, if we have to go without him for a period,’’ Kubiak said, “we’re going to have to really ask some guys to step up to the plate.’’

The Steelers may have to do the same without their franchise quarterback.

Roethlisberger was beat up all day, sacked five times behind an offensive line missing two regular starters. The Steelers also lost running back Rashard Mendenhall (right hamstring), linebacker James Harrison (right eye), and defensive end Aaron Smith (foot sprain) during the game.

Roethlisberger played until the end, but he was wearing a protective boot on his left foot afterward.

Banged up or not, Harrison ripped the Steelers’ performance.

“I’m not happy with any of it,’’ Harrison said. “It’s a loss. I’m not trying to look for a silver lining in any of it. We played like garbage. Period. We stink right now.’’

Foster, meanwhile, finally looked healthy after weeks of nursing a left hamstring strain. He broke a 42-yard touchdown run early in the fourth quarter after the Steelers rallied to tie it at 10. Foster finished with 30 carries.

“It was my first game back, really, fully, and I felt 100 percent,’’ Foster said.

Matt Schaub threw a scoring pass to Owen Daniels in the first half. The Texans led, 10-0, at the break, and an ill-timed penalty cost them another TD.

On the final snap before the half, Danieal Manning blocked Shaun Suisham’s field goal attempt, and Johnathan Joseph scooped up the loose ball and ran 61 yards to the end zone. But Manning was flagged for an illegal block well behind Joseph, and the score was nullified.

The Texans had nine penalties for 64 yards.

“A lot of times, when those things happen to teams, they can’t overcome them,’’ Kubiak said. “That wasn’t the case today.’’

Houston was on the move in the second quarter when Johnson pulled up without getting touched.

The five-time Pro Bowl receiver was down on the field for several minutes, hushing the home crowd and the Houston sideline. He limped off to applause and walked to the locker room.

Without Johnson, Schaub looked for Daniels again and completed a 30-yard pass to his tight end early in the fourth. Foster took it from there, breaking outside and outrunning the Pittsburgh secondary on a 42-yard sprint to the end zone.

Antonio Smith and Mario Williams sacked Roethlisberger, and linebacker Connor Barwin swatted away his fourth-down pass with 2:38 left.

The Steelers had one last gasp after Houston had another touchdown wiped away by a penalty. Joseph intercepted Roethlisberger’s pass from the end zone and returned it for a score, but rookie J.J. Watt was flagged for roughing the passer.

The Texans got an interception that counted by Jason Allen to clinch the win.