"There will be a lot of movement in the summer, as with any club that gets relegated. I've not had much first-team football at Derby, which basically cost me my international place," he told the South Wales Echo.
"People know what playing for Cardiff meant to me and I need regular football to rekindle my international career. The summer will be very interesting and returning to Cardiff does excite me.
"We will have to see what happens in the summer but I'm not ruling out returning to Cardiff. Never say never is the saying and stranger things have happened in football, that's for sure."