City won 2-1 in a below par performance.
But Walker said, “When they play five at the back, it's always going to be difficult to break the spaces but I'm glad to have scored.
“I didn't get on the score-sheet last season so it's a happy moment for me.
“Today we adapted the system which helped me a lot and helped me get forward. It was enjoyable out there and it was important to bounce back and get the three points after a disappointing fixture at Wolves.
“But when teams set up like that you are always going to get down on the counter-attack and its something we need to improve on.
“We've been done more than last season so there's still cobwebs out there to brush off from the summer.
“We're all working hard and training hard on the tactics so hopefully more to come and will come good after the international break."