Jones-Drew told the club's official website: "I have a ton left in my game. I think people tend to look at running backs and say, 'Oh, you're 29. You don't have anything left.'
"Well, last year I was coming off a major foot surgery, which most people don't even play the year after and I played 15 games and I didn't get an off-season to work out. I just kind of toughed it out throughout the season and did everything I could to try to help us be as successful as possible.
"So, only being the starter for three years and a back up for three, I feel like I have a ton left in the tank. I get an opportunity to show that here in Oakland."
Jones-Drew ran for 803 yards and five touchdowns for the Jags in the 2013 season.