Joseph, who is listed as a starter on Houston's depth chart, sat out the preseason and was limited in preseason practice after having surgery in December to repair a torn ligament in his toe.
Joseph was asked if he was completely healthy.
"Somewhere along the lines," he said, according to ESPN.com. "...You're never 100 percent in this league."
The two-time Pro Bowler recorded 47 tackles and three interceptions over 15 starts last season.
The Texans finished with an NFL-low two wins in 2013.
- Chris Johnson