INDIANAPOLIS -- Colts quarterback Anthony Richardson cleared the NFL's concussion protocol Friday and will start Sunday's game against the Los Angeles Rams, coach Shane Steichen said.

Richardson suffered a concussion in the first half of a Week 2 win over the Houston Texans after slamming his head on the turf as he scored his second rushing touchdown of the game. He missed the Colts' Week 3 victory over the Baltimore Ravens but returned to practice Wednesday and was a full participant in each of the past three workouts.

Richardson flashed repeatedly in his brief time in the lineup, which has been limited to the first six quarters of the season. He became the first Colts rookie quarterback to rush for touchdowns in each of his first two games and is the third quarterback in NFL history to record three or more rushing touchdowns in his first two games.

"Last week was a little rough for me," Richardson said of missing the Baltimore game. "I love football and couldn't go out there with the team, so it was eating me up inside. But I'm excited to be back."

Richardson's physical style of play has become a topic of discussion after he left the Colts' Week 1 game against the Jaguars in the closing minutes following a hit to the knee. Against Houston, he suffered the concussion while running the football and failing to anticipate a hit from an oncoming safety.

"The injuries I've gotten so far, it's nothing major," Richardson said. "I banged my knee on the turf. Everybody gets hurt on turf. And then I hit my head on the ground. I don't think I should change the way I play. I think I play smart enough to know when to get down."

Richardson self-reported his concussion after initially returning to the Houston game, saying he felt a bit of a headache but eventually asked trainers to check him out.

"I didn't want to hurt the team and continue to play," he said.

On Sunday against the Rams, Richardson's job might be tougher than initially thought. Center Ryan Kelly, who also suffered a concussion in Week 2, did not clear concussion protocol after practicing Wednesday and Thursday, and his status remains in limbo. Left tackle Bernhard Raimann developed concussion symptoms late this week, Steichen said, and is also a question mark for Sunday. And right tackle Braden Smith suffered a hand injury that kept him out of Friday's practice.