"He's been a pivotal part of Doncaster's success as they've risen through the leagues, which is reflected in how hard they have fought to keep him there. The player has displayed a hunger to me to play at the highest level and a desire to play and do well for Derby County."
"He is just the type of character I want in my dressing room and I'm delighted we've secured his signature."
Green said, "I have enjoyed fantastic times at Doncaster and I can't speak highly enough of the people and the fans there - they have been great to me."
"However, this is a new chapter for me and something that I felt I had to do. Paul Jewell has shown me the ambition he has for this club and I feel that we could really achieve something here."