Clowney was inactive with an illness for Houston's game against the Philadelphia Eagles on Sunday, a 31-21 loss at home.
It was Clowney's seventh missed game this season, after he missed six games recovering from a torn meniscus he suffered during the Texans' season-opener, a 17-6 win over Washington at home.
"I don't know anything about those reports, I just know what I see," O'Brien said after the Philadelphia game. "I see a rookie player that is injured and is trying to come back from injury and he had a little setback this week with the flu and hopefully he'll be back ready for Cleveland."
"He's had a couple injuries here and a concussion, some of that is bad luck. He got knocked in the head in the Denver training camp, he got a sports hernia injury, he's got a knee [issue], that's what I think it is."
"I think the world of Jadeveon Clowney. I don't think there's anyone here that's frustrated with [him]."
So far this season, Clowney has appeared in two regular season games. He recorded one tackle, a stop for a loss, in the Week 1 game against Washington. Against the Titans in Week 8, the linebacker notched just one tackle in 32 defensive snaps.
O'Brien was asked prior to the Philadelphia game if Clowney's absence from the field for another week was frustrating. "No it's not frustrating at all," O'Brien said. "Nope, not one bit. It's the National Football League."
While at the University of South Carolina, Clowney was the 2012 SEC Defensive Player of the Year and a 2013 first-team All-American.
- Christopher Woody & Molly Geary