Anyone looking at Joshua Brillante’s photo at the website of his club Newcastle United Jets a few months ago would have seen a well-groomed, freshly shaven, short-haired youngster with a gentle smile. The young Australian looked every inch the kind of person with whom you could leave your children, your dog or your house keys, someone you could trust without a moment’s thought.

Take a look at the 20-year-old Aussie now, however, and you might not feel so inclined to put your valuables in his care. In fact, you might be inclined to take one look at him and run.

The reason? Well, the affable smile and warm look in his eye are still there. The only thing is, they are not as easy to discern beneath the thick beard that now covers the lower half of his face and the shaggy, unkempt hair tumbling over his forehead.

It is quite a transformation, one that might lead you to believe that this hirsute young man and the clean-cut, fresh-faced footballer in the club website are two different people. As can confirm, however, they are one and the same.

“Yes, people can be a bit taken aback when they see me for the first time,” said the laughing central defender, whose good humour could partly be put down to his side’s fine 1-1 draw with Colombia in their Group C opener at the FIFA U-20 World Cup Turkey 2013. “Most people find it hard to believe that I’m only 20.”

Watch him on the field of play, however, and there is no doubting his age. The hard-running Brillante made an energetic contribution at Trabzon’s Huseyin Avni Aker Stadium on Saturday as the Australians left the Colombians chasing shadows for the best part of an hour. Dispatching his defensive duties with élan, he also powered forward on several occasions, playing his part in some of Australia’s best moves, shooting just past the post on one occasion and sending in a pinpoint cross that team-mate Connor Pain failed to make the most of.

I promise that if we win the World Cup I’ll shave the whole lot off: hair and beard.

Joshua Brillante's Turkey 2013 bet

A true team man, Brillante is hard on himself when he misses an opportunity and quick to encourage his team-mates when they fail in front of goal. “I would have loved to have scored or got an assist because it doesn’t happen to me that often. It would have been even nicer in a World Cup match too,” said the Young Socceroo with the caveman looks. “It wasn’t to be this time, but in any case it’s the kind of thing you forget when someone does manage to score, whoever they are.”

Against the Colombians it was Daniel De Silva, the youngest player in the tournament at only 16 years and three months, who got on the scoresheet for the boys from Down Under. Brillante was only a year older than that when he made his professional debut for Gold Coast United in 2010, a game in which he served notice of his combative style by picking up a yellow card after only half an hour. “It was a tackle I timed badly, though I had a good game overall,” he said of the caution.

Thrown in at the deep end in the Australian league, the young Brillante quickly got acclimatised. Over the following two seasons he picked up some valuable experience that has stood him in very good stead for the world finals. “It has given me an advantage, because everything’s taken to a very high level: the commitment, the pace of the game and the tactics,” said the player, who describes compatriot Harry Kewell as his role model. “When you play in a professional league you go out on the pitch to win, and that type of attitude is really helpful when you take it into a World Cup.”

When asked if his bushy hairstyle and beard disconcert opposing players, he said: “I don’t know if it scares them but it definitely gets me noticed. I guess there are some players who feel a little uneasy when they see me. What I’m worried about now is my team-mates not recognising me if I ever decide to have a shave or get my hair cut.”

That could be happening sooner rather than later if things continue to go well for the Australians, with the tousled terror putting his hair on the line as he made a bet with “Ok, ok. I promise that if we win the World Cup I’ll shave the whole lot off: hair and beard. Write it down so there’s proof.”

You’re on, Joshua. That is our side of the deal kept. The next couple of weeks will reveal if you have to keep yours.