The Houston Texans have placed linebacker Keyaron Fox on injured reserve with a knee injury.
Fox suffered the injury during Wednesday's practice and will need surgery.
"It's going to have to require some surgery here at some point," Houston Texans head coach Gary Kubiak said. "I don't know when that'll be. I'm sad for the kid. He got rolled up in a drill. I think he's been playing eight or nine years so you hate to see that happen, but we'll take care of him and he'll be a part of our team this year."
Fox started his NFL career with Kansas City in 2004. He played four seasons with the Chiefs before going to Pittsburgh for three years.
The Georgia Tech product, who played for Washington in 2011, has 180 tackles, one sack and one interception in 98 career games.
To take Fox's spot on the roster, the Texans signed linebacker Omar Gaither.
In 77 career games with the Eagles (2006-10) and Panthers (2011), Gaither has 320 tackles, six sacks and two interceptions.