HOUSTON -- After Houston Texans quarterback Tom Savage took a hit that kept him on the ground with his hands twitching, he was allowed to re-enter the game in the 26-16 loss to the San Francisco 49ers. A series later, Savage was taken to the locker room and later ruled out with a concussion.

Texans head coach Bill O'Brien said Savage was checked immediately after the hit, but was cleared by the unaffiliated neurotrauma consultant to return to the game. After the following series, Savage was tested again and it was determined he needed to leave the game.

"[They] made the determination that he was OK," O'Brien said. "Not me, obviously the evaluators made the determination to put him back in the game. He went back in the game and came out and they evaluated him a little bit more just because of what they saw."

"Whatever [the evaluators] see and the testing that they do they try to make the best decision with the player and they weren't satisfied with the results of the second test so they decided to pull him, and that's when he went into the locker room."

Savage was hit by 49ers defensive end Elvis Dumervil while throwing an incomplete pass on third down. He appeared to have trouble getting up and seemed dazed, and his hands were visibly shaking.