"It's a hamstring," said Foster, who entered the game leading the AFC with 531 yards rushing. "It doesn't seem too severe right now, so we will just play it out. I have a bye week coming. It's tough."
Foster's injury happened in the first quarter, and after leaving the field to be evaluated, Houston's top back returned to the sidelines in sweatpants and a sweatshirt, his pads and uniform off, finished for the day.
Foster had four carries for 11 yards before leaving.
Despite the fact Foster was on the injury report with a hamstring issue last week, the Texans only kept two running backs active for Sunday's game.
Rookie Cierre Wood was inactive.
The Texans also lost linebacker Brian Cushing on Sunday.
According to multiple reports, he's out for the year after suffering a broken left leg and a torn LCL in his knee.