Australia coach Holger Osieck has another left fullback option with Adelaide's Brazil-born defender Cassio eligible for the Socceroos after becoming an Australian Citizen.
Cassio, who attended a ceremony with his wife and two sons at Hindmarsh Stadium on Friday morning, spoke of his desire to play for the Socceroos should the opportunity arise.
'My first aim is just to be Australian," Cassio said. "If a Socceroos call up came it would be a dream, but I have to work hard every day.
"I have a lot of respect for the players that are in the national squad now, so if I train and play well, then the coach might look at me."
Cassio and his family were welcomed as Australian citizens by Federal Member for Hindmarsh Steve Georganas MP after making a pledge of commitment and loyalty to the Commonwealth of Australia in front of a host of friends and Adelaide United team mates.
'I’m so proud. This is a real special moment for me and my family," Cassio said.
'I remember the first time I stepped into this country and especially into Adelaide in 2007, I remember telling my wife that I had really good feelings coming to Australia and hopefully we stay here for more than one year."
'We’ve been here for five and a half years and it has been hard staying away from our families back in Brazil, but I’ve found new friends and new family here and that makes me feel so good and I’m very proud at this moment."
Before being identified as a possible signing for the Reds prior to the 2006-2007 season, Cassio admitted he never thought he would be one day calling himself Australian and Adelaide home.
'Playing football brought me here to Australia, to Adelaide United, and I’m so thankful to Adelaide United for bringing me here and that’s where it all started from," Cassio said.
'I would never have imagined that I’d come here to play soccer and now I’m an Australian citizen."
'It’s not just about the soccer but about lifestyle as well, I really love being here."
'I would hate to think that if I left Australia and wanted to come back that I couldn’t come back permanently, but now I can come and stay here anytime. I feel like a real Australian now."
Cassio will still be registered as a foreign player for the remainder of the Reds’ 2012 AFC Champions League campaign, as regulations for the competition stipulate that a player must have obtained the nationality at least one year prior to the opening match day of the competition.
The 32 year-old only qualified to be able to apply for his citizenship on the 17 August 2012.