Tom Savage
Tom Savage was drafted by the Texans in the fourth round of the 2014 NFL Draft. Getty Images

Houston Texans quarterback Tom Savage re-entered Sunday’s game against the San Francisco 49ers following a tackle that left him convulsing on the field.

Savage, 27, was briefly evaluated by officials in a medical tent after he appeared stunned by a hit from 49ers defensive end Elvis Dumervil on a pass attempt with nine minutes remaining in the second quarter. He checked back into the game where he threw two incomplete passes.

Savage was pulled from the game again and proceeded to the locker room where he was ruled out with a concussion. Afterward, he was seen trying to re-enter the game but was replaced by quarterback T.J. Yates.

"Savage was injured on the last series. He went into the sideline tent for a quick evaluation but returned without missing a down. Now he's in the locker room. He was evaluated for a concussion at Tennessee last week at halftime but played," McClain tweeted.

Many took to Twitter with reactions to Savage's incident.

"Disgusted that the @HoustonTexans allowed Tom Savage to return to the game after 2 plays after showing these horrifying #concussion signs (is that a seizure?) after a head impact. I would not let my worst enemy go through the 2017 #NFL sideline concussion protocol," Chris Nowinski, Ph.D. tweeted from his ‏verified account.

The NFL’s in-game concussion protocol tests players for the injury before they are permitted to return to play. It is a five-step process conducted on the sideline following a hit, which tests cognitive ability, awareness, and signs of a concussion.

In 2016, NFL Commissioner Roger Goodell announced the "Play Smart. Play Safe" initiative to bolster player's safety.

"Rightfully, much of the public discussion is about concussions — how they happen, how they can be prevented and treated and what is known about their long-term impact," Goodell wrote in a letter addressed to fans. "The NFL has been a leader on health and safety in many ways, and we’ve made some real strides in recent years. But when it comes to addressing head injuries in our game, I’m not satisfied, and neither are the owners of the NFL’s 32 clubs. We can and will do better."