Mullen has re-signed with the Reds for a further two years, and the 19 year old is now set to remain at United until at least the end of the 2010/11 season.

Mullen was a member of the Young Socceroos squad that recently qualified for next year’s FIFA Under 20 World Cup in Egypt after they reached the Semi Finals of the AFC U19 Championships.

Since initially signing with the club at the start of the 2008/09 Season, Mullen has made three appearances in the Hyundai A-League, his latest being on Saturday night when he helped United to a clean sheet and three points over Sydney FC.

While he displays maturity beyond his age, Mullen showed signs of his full potential when he started in United’s home leg against Uzbekistan’s Bunyodkor in the Semi Finals of the AFC Champions League.

The right sided defender is the son of former Adelaide City NSL legend and current United Youth Team Coach Joe Mullen.

He will be staking his claims for another starting berth for the Reds when they go up against Newcastle Jets at EnergyAustralia Stadium on Sunday.