The Toffees were defeated 2-0 by Roberto Mancini's side, having held firm for almost 70 minutes, with Mario Balotelli and James Milner netting the goals for the home side.
It was a feisty encounter at the Etihad Stadium with five Everton players - including Rodwell - being shown yellow cards.
Rodwell, meanwhile, was disappointed to leave Manchester with nothing to show for it - although he is now focused on the clash with Liverpool.
“It was disappointing,” said the 20-year-old. “We had our game plan and it worked for 70 minutes.
"They got the goal and it knocked the stuffing out of us and it was very difficult to come back from that.
“They have got a lot of money now and have bought some very good players. They have a strong squad but we have a strong squad as well. We tried to match them but it wasn’t to be."
The midfielder added: “We have made a decent start and got some good victories under our belts so we won’t get too down about this and we will focus now on the Liverpool game.
“We had a match in midweek which went to extra time so that was a hard workout. Man City was again another hard workout but we will have a rest, get into a good week’s training and bounce back for the derby.”