Aussie Triallist in toon?

Just found this online in some Australian Newspaper site, not much detail, and I have no idea what a left stopper is, but could be interesting to see if this works out. His name is Good so if his name is anything to go by, he may be decent

http://www.theage.com.au/sport/soccer/newcastle-beckons-for-the-good-at-heart-20120416-1x3ra.html
MELBOURNE Heart teenager Curtis Good could become the next Australian in the Premier League if a fairytale opportunity to join one of England's best known clubs, Newcastle United, comes to fruition.

The youngster has flown to England for a short trial with the club, which is chasing a top four finish and a Champions League spot for next season.

Good, 19, will spend just over a week with Newcastle, where he is due to train with the first team, giving coach Alan Pardew the chance of a first-hand look at the defender.

Good is a junior Australian international who joined Heart from the AIS.

Tall, strong and good in the air, the left-sided Good is versatile and able to play as a left stopper or at left back.

 

I now need to know what a left stopper is. The Aussies have got some way to go to catch the americans in introducing new terms to football though.

 

Believe it means left sided centre back. 4-4-2 formation.

 

hope he is GOOD