But the 32 year-old, released by boss Andy Scott in the summer, insists "there's no hard feelings."
The now Morecambe player spoke ahead of next Tuesday's clash at the Globe Arena, and said: "I didn't want to leave Rotherham and it was a surprise when I was let go. I had a great time there and a decent rapport with the fans and I always gave 100 per cent but a new manager came in and there were a few things he wanted to change and that's his prerogative. It's time to move on."
Fenton signed a two-year deal with Morecambe, combining his playing with his studies for a physiotherapy degree in Manchester and added; "We were underestimated at the start of the season. Pundits were making us second or third favourites for relegation but I looked at the squad here and thought we could challenge. It's been enjoyable."
The Millers won't be facing another old face in Kevin Ellison as he has picked up a leg injury, with Fenners adding; "He's been on fire and he'll be a big miss but I can't wait for the game because it's always special to play against your old club. I still keep in touch with the boys and I look for Rotherham's results every week. I'd like to see them do well, apart from Tuesday."