HOUSTON — Jadeveon Clowney, the No. 1 overall pick of the Houston Texans, will be out 4-6 weeks after arthroscopic surgery on his right knee Monday.

Coach Bill O’Brien said he didn’t know exactly what was repaired in Clowney’s knee when asked if it was a torn meniscus.

“I’m not a doctor so I don’t know,” O’Brien said. “It’s just something they went in there and tried to fix it. It seems like it went well.”

Clowney, who had one tackle for a loss, was injured late in the second quarter in Sunday’s win over the Washington Redskins. He was hurt when he jumped up to try and bat down a pass. He put his hand to his right knee and began limping after he landed.

Some have speculated that his foot slipped between one of the 8-by-8-foot palettes of real grass that make up Houston’s field. If that was the case, O’Brien said he didn’t know about it.

“He didn’t say anything to me about that,” O’Brien said. “From looking at all the angles on film, he just came down awkwardly. Most of those types of injuries are non-contact.”