Houston, TX (SportsNetwork.com) - The Houston Texans officially moved rookie linebacker Jadeveon Clowney to injured reserve on Wednesday, two days after he underwent microfracture surgery on his injured right knee.

Clowney will miss nine months, with the Texans looking at early September as a possible return period for the No. 1 overall draft pick, who tore his meniscus in Week 1 against Washington and missed the next six games following surgery.

The injury persisted, limiting Clowney to just four games in his first season.

Clowney, 21, totaled just seven tackles without a sack.

The Texans signed rookie linebacker Jason Ankrah from the practice squad to take Clowney's place on the roster. They signed defensive end Kourtnei Brown to the practice squad.