Anthony Richardson might have been on his way to a historic day Sunday.

Richardson became the first Indianapolis Colts player since 1999 to rush for two touchdowns in the first quarter of a game. He had 56 passing yards, 35 rushing yards and two rushing touchdowns in one quarter against the Houston Texans, and while you can get in trouble prorating stats like that for four quarters, it was looking good for the Colts rookie.

Then Richardson was out of the game due to a concussion, and that's becoming a concern. He was still in the concussion protocol Wednesday and was unable to practice. That's not a great sign for his availability for Sunday's game, but he has a few days to be cleared and start against the Baltimore Ravens.

Even if Richardson is cleared and starts Sunday, it doesn't diminish the concern that he has played in two NFL games and has had to leave both due to injury.

Late in the Colts' season opener, Richardson banged his knee and left the game. That didn't turn out to be serious, but seeing him suffer a concussion at the end of a touchdown run, when he hit the back of his head on the turf, is a bit more troubling.

The Colts have put a lot of chips on Richardson, drafting him fourth overall and asking him to be the next face of the franchise. As they learned with Andrew Luck and his too-short career, injuries can ruin those plans.

"You're always concerned," Colts owner Jim Irsay said Sunday, via ESPN.com's Stephen Holder. "The first game, he banged up the knee, but it was OK, just a contusion. This game, banging the head. I think it's just something where he's got to protect himself. He's a big, physical guy. Obviously, he can run the football, and guys do a lot of running now at that position. And so, I think self-protection is an issue."

Richardson is off to a very good start in his NFL career. He was drafted high because of his immense physical skills coming out of Florida, and those have been on display through two weeks. He looks like he has a bright future. Now he just needs to stay healthy.