Houston Texans linebacker Jadeveon Clowney has revealed that he is "encouraged" by his recovery from a knee injury which prematurely ended his rookie season.

The 22-year-old was selected with the first overall pick in the 2014 Draft, but his time on the field was limited by injuries as he was forced to undergo microfracture surgery on his knee in December.

Reports suggested that the linebacker could be ruled out for up to 10 months, but Clowney refused to confirm when he would be available for action once again.

"I'm not going to speak on that, but I'm making progress, and I'm very encouraged," he told the Houston Chronicle. "I'm working hard, but we're not going to rush it.

"Man, I thought that was going to be real tough, but I had my family around a lot.When they finally told me I could walk, I just took off.

"I'm progressing well. I'm moving forward in my rehab. Things are starting to come together just like I hoped they would."

Clowney recorded seven tackles in his first season in the NFL.