The Magpies have steadied the ship in the past couple of weeks after a poor start to the season.
But Bruce knows there is still a lot of work to do as he reshapes the first team in his image.
Reflecting on his first few weeks as Magpies boss, Bruce told the Chronicle: "The one area we are going to have to put a lot of work into is in defence.
"Our defensive organisation has to be spot on to give yourself any type of platform.
"I think we had Leicester, Tottenham and Arsenal in the space of a week recently and they managed five shots on target against us.
"So that's a positive thing.
"We we will have to keep it to that and make sure those standards stay high.
"The next step, which will take weeks and months, is the hardest one.
"It's creativity and that little bit of something that will cause a threat to other teams."