Foster was injured on a hard hit to the head with about four minutes left in the second quarter. He was checked for a concussion on the sideline and returned to the game two plays later before leaving again, this time going into the locker room to undergo the league's concussion protocol.
Foster was visibly frustrated on the sideline, grabbing a tray of beverages and slamming it onto the ground before going inside.
After passing the test, Foster returned for the second half. He finished with 41 yards rushing and 77 yards receiving.
"I didn't get it done in the clutch situations," Foster said. "We have to take accountability for that and keep on pushing. It was a tough game. It's a tough league, so you've got to keep on pushing and believe.
"You don't want to start 1-4, but it's a long season, and in order for you to even have the opportunity to finish how you want to, you have to believe it. I do, and I know the rest of my teammates do, so we just got to keep pushing."
This was Foster's second game this season after he missed Houston's first three games while recovering from groin surgery.
ESPN Texans reporter Tania Ganguli contributed to this report.