AUSTRALIAN coach Tim Nielsen has implored young tearaways Phillip Hughes and Steve Smith to realise they cannot always approach Test matches like kids riding billycarts without brakes.

"There'll be times they can't walk in and blaze away and get the results we want, and we need to make sure they understand that," Nielsen said.

"Young players, having played all the different forms of the game at the level below, often get away with just sheer talent and overpowering the opposition. If they get through the best bowler in Sheffield Shield, there isn't necessarily the depth they have at international level and their skill and talent often takes over.

"The depth of international cricket can find you out in that regard. It's the golden question, how do you fast-track the younger players to perform at the highest level as quickly as you possibly can?

"The only way that we can do that is by playing them. They're not going to learn it by playing for their states, or going to the nets. Getting it done faster will rely on us being patient in the short term, giving them opportunity, not expecting miracles overnight and ensuring every time they play a game, they learn and don't keep making the same mistakes."

Hughes and Smith have enough talent in their respective big toes to make fast runs in Test cricket when pitches resemble the Hume Highway and opposition attacks are running on empty. The real battle is finding a way to knuckle down and play for survival when pitches and bowlers get the devil inside.

"We need to understand you can't just do it for 12 overs or 15 overs," Nielsen said. "It's got to be two hours, then four hours and eight."