Sam Allardyce is worried Newcastle's traditional defensive problems may see his first campaign at St James' Park deemed a failure.
Five away games have yielded just one win, and three defeats, with Newcastle's backline failing to keep a clean sheet in the process.
"We are still conceding too many goals, especially away from home," he said in the Northern Echo.
"That's my main area of concern. We have not kept a single clean sheet away from home.
"It did not matter at Bolton on the opening day because we scored three goals and won the game but we can't afford to keep doing that.
"The Man City game was the perfect example. We could not hold on to draw, even though we went a goal up. We have to play a bit tighter when we are a goal up.
"It's been a problem for Newcastle teams in the past. It's something we have to get right if we are going to be successful."