Paul Green admits it was a tough decision not to renew his contract at Derby but feels the time is right for a new challenge.
The 29-year-old midfielder has been with the Rams for four years and a number of npower Championship clubs are believed to be interested in the Republic of Ireland international.
"I have been here four years and had some great times, and the fans have been absolutely fantastic with me," he told the Derby Telegraph.
"It's a really tough decision to go because this is a big club, one of the biggest in the Championship.
"I have got good friends here at Derby and we have a great team spirit but a fresh challenge elsewhere is what it came down to in the end.
"I sat down with my family and discussed it and came to a decision that it was time for a change.
"I had to think about my family as well."