Montee Ball has described his fumble against the New York Giants as a "huge rookie mistake".
The Denver Broncos running back, who was a second-round Draft pick earlier this year, lost the ball just short of the endzone during the AFC West side's 41-23 victory last weekend.
The 22-year-old told the team's official website: "For me, it was just a lack of focus, a huge rookie mistake. My eyes got big because I saw the end zone, I got lazy with the football and it popped out.
"We definitely corrected it. I've been working on ball security all week. It's never been an issue with me. The coaches talked with me and said that it's never been an issue with me, that's why they drafted me.
"They told me to make sure to pay more attention to it, put a lot of emphasis on it, on carrying the football. That's the number one thing for a running back, ball security. I went to the sideline, everyone encouraged me and I went back out there and kept playing."
The Broncos play the Oakland Raiders tomorrow.