O'Brien will call plays again after taking the duties away from offensive coordinator George Godsey for the game against the Tennessee Titans at NRG Stadium, according to John McClain of the Houston Chronicle and confirmed by multiple reports.
O'Brien called plays in 2014 in his first season with the Texans, but turned over the responsibility to Godsey last year.
On Friday, O'Brien would not confirm he has taken over play-calling duties.
"I'm in charge of every play that goes into the game," O'Brien told reporters. "You'd be amazed at how many defensive calls I've made, how many special teams calls I've made and how many offensive calls I've made in the years that I've been here. And most of them haven't worked, let me put it to you that way. So it doesn't matter who calls the plays. It's about the execution, it's about going out there and playing good football.
"As a head football coach, that's what you're paid to do -- to be making sure that the calls that go into the game are basically approved by you as the head football coach. So none of that matters. I don't even know why that's a story. It's not a story. Nothing has changed."
The Texans are coming off the 27-0 Week 3 loss to the New England Patriots.
"We really have to go back as a coaching staff and really look at what we did, learn from it, and try to fix it," O'Brien said after the blowout loss. "We really need to put our heads together and get after it and get better for the next game, no doubt about it."
Through three games, the 2-1 Texans have scored only three touchdowns, all on quarterback Brock Osweiler passes. Houston has scored 42 points, tied with Tennessee for the fewest in the league.
The Texans are 24th in offense -- 13th rushing and 27th passing -- and they are ranks in red-zone touchdowns, with just one in seven tries this season.