DJ Hayden has been cleared for full contact practices nine months after suffering a life-threatening heart injury.
The Oakland Raiders cornerback, who was a first-round pick in this year's draft, tore a vein in his heart during a practice in college last November.
Head coach Dennis Allen told The AP: "Obviously, nobody knows how he's going to respond when that happens. He's been very good as far as practice has been concerned."
The injury, which is typically only seen in those involved in car crashes, is estimated to have a 95% fatality rate.
The 23-year-old recorded 61 tackles in nine games during his final college season.