Defender Chris Riggott has signed a one-year deal with Derby County.
The injury-plagued centre-half, 30, left Cardiff City in January but has impressed while training with the Rams during pre-season.
Manager Nigel Clough told the club website: "We said all along that as long as he proved his fitness, we would get him signed up.
"Chris hasn't played in almost two years so we have to be a bit patient getting him back to match sharpness."
Former Rams trainee Riggott left Pride Park for Middlesbrough in 2003.