"I'm happy to get on the scoresheet and obviously happy to get the three points, which was the main thing coming up here," said Walker, who did not celebrate his goal.
"My mum and dad live here, so if I'd celebrated I'd have got a lot of stick. I'm a Sheffield United fan, so I couldn't celebrate.
"I'm enjoying my football. We don't sit back and defend. We want to score three or four, but it's great to get the clean sheet on the board as well."
"If people think we can go toe to toe with Man City they're deluded, really deluded," said Sheffield United boss Chris Wilder.
"We have to find a way to catch up with these teams who have spent about a billion pounds on their structure and their players.
"It's frustrating because I think we've got a lot more quality in those areas."