Full-back Kieron Freeman has signed a new three-year contract which keeps him at Derby until the summer of 2016.
The 21-year-old Wales Under-21 international joined last summer from local rivals Nottingham Forest and has so far played 15 games for the Rams.
Manager Nigel Clough said: "Kieron is a player we have a lot of faith in.
"He's got all the right attributes to be an extremely good defender. We're pleased with his progress and he's not looked out of place in the first team."