"I'm really looking forward to this one," Mears told Derby Telegraph. "It will be great to go and play against Man City. I've got a lot of good friends there, not just players but the staff as well. It's like home for me really.
"I wasn't a Manchester City fan. My family was the other side but my time with City did change me a lot.
"I did support Manchester United but being at City, the passion of the fans was unbelievable and I've always got a small place in my heart for them."
Mears made one appearance at City before joining Preston North End in 2002, where he linked up with Billy Davies, now boss of Derby.
It came at Maine Road, meaning tomorrow's fixture will be Mears' first experience of the City of Manchester Stadium.
"The season I left, I got to make my debut at Maine Road," he said.
"I never played at the City of Manchester Stadium - they moved there just after I left. Kevin Keegan was the manager, then.
"I got to come on against them as a sub when I was at West Ham but, hopefully, tomorrow I will start and I can show them what I can do.
"I look back at a club that is really close to my heart but I will be going to take three points."