Arizona Cardinals defensive back Tyrann Mathieu has admitted that it feels good to be back to full fitness after a year struggling with an ACL injury.

The 23-year-old tore his ACL towards the end of the 2013 season, and his recovery forced him to miss time in the 2014 campaign, where he struggled to find his best form.

However, Mathieu has insisted that he now feels back to his best and is raring to go for the new season.

Mathieu told reporters: "It just feels good to be free. You try to stay as optimistic as possible but there is a reality to it, too.

"It's kind of hard to keep telling yourself it's going to be all right, especially when we got into the thick of everything last year, thinking that if I was 100%, I'd probably be able to help my team a whole lot more than I'm doing right now."

Mathieu has recorded 106 tackles, one sack and three interceptions in his two-year NFL career.