Midfielder Craig Bryson has agreed a new three-year contract with Derby.
Frank Lampard hopes Chelsea team-mate John Terry can follow him by signing a new contract with the club.
Leeds goalkeeper Paul Rachubka has returned to Accrington on loan until the end of the season.
The 31-year-old former Blackpool and Huddersfield goalkeeper made six appearances for Stanley while on loan before Christmas.
"I'm just glad it's all sorted now and I can concentrate on the football," Rachubka said.
"It's been a long couple of weeks and the weather hasn't helped and I just want to get back playing and back into the routine of being involved in first-team football.
"All the lads have welcomed me back and it's been great. You know what you're dealing with and there's no settling in to do."
Rachubka, who has made only seven first-team appearances for Leeds since joining from Blackpool in the summer of 2011, is expected to go straight into Accrington's squad for their clash with Port Vale this weekend.