Tarek Elrich honoured to wear Ahmad's 21

Tarek Elrich's connection to brother Ahmad will grow even stronger when Australia take on Kyrgyzstan in a World Cup qualifier on Tuesday.

With star midfielder Massimo Luongo injured, Adelaide United defender Tarek has been handed the number 21 shirt.

It is the same number his brother, a 17-time Socceroo, donned in the green and gold and same number Tarek wears at Adelaide.

Getting that opportunity means a lot to Tarek, who always wanted to be like the now-retired Ahmad.

"Ahmad's always been an idol of mine," Tarek told FFA TV.

"When people say, 'Who do you look up to?' Other than my father of course who gave us everything, my brother Ahmad was always someone I wanted to be like.

"I always had that in the back of my mind that I wanted to represent my country and follow in my brother's footsteps.

"I thought that was cut short and I wasn't going to get that chance, but it shows with hard work and determination anything is possible.

"I'm glad I've come into camp and, I'm a bit upset that Mass is injured, but in saying that Dom [Socceroos equipment manager Dom Rabsch] messaged me saying that Mass isn't coming and if I'd like wear 21 which is obviously Ahmad's number when he was playing with the Socceroos and it's a number I wear at Adelaide as well in honour of my brother.

"It's something that every time I put that number on I remember him and think of him.

"He's someone that's done very well in football, played at the highest level, and hopefully it's just the start for me and I can keep going."

Tarek, 28, is in Socceroos camp in Dubai preparing for the qualifier against Kyrgyzstan.

The full-back said Ange Postecoglou's men were ready to go, still hurting from failing to overcome Macedonia in a friendly in March.

"No Aussie team has played against them yet. Ange, first thing he touched on, he said it's not going to be easy," Tarek said.

"We're going to go out there field our best team and play our hardest game. There's no such thing as an easy game at international level. It's so true.

"Against Macedonia we failed to score and get a good result. He's touched on that and that's hurting us players.

"We want to make sure we put on our green and gold, we play our best, we give it our all and most importantly, win."