Jake Buxton will join the Rams from Nigel Clough's former club Burton Albion this summer.
The 24-year-old played a key part in the Brewers' promotion to the Football League and has been rewarded with a shot at Championship football next season.
"Jake's attitude is first-class and we hope he will surprise a few people," said Clough.
"He does not have the experience at this level but he will make up for that with the desire and heart he has."
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