To have one Olympian in a family may be a happy turn of fate, but to have two cannot be attributed to mere coincidence.

Kieron Achara will savour the greatest opportunity of his basketball career when he steps onto the court on Sunday as Great Britain begin what many expect to be a tough challenge at the Games. Watching on will be his greatest cheerleader, his brother Idris, who has marched this path before.

Achara, then at university at Pittsburgh, remembers his own sense of pride as he followed his elder sibling at the 2000 Special Olympics in Athens, where Idris was competing in basketball for Team GB. Both were born in Nigeria, where their father was a high-ranking government official. When he left, their mother Marion took her children back to her native Scotland, opting to accept the challenge of single parenthood.

"If you ask me who my biggest hero is, it's my mum," Achara states. "She worked two jobs at times. Plus I was very fortunate that my grandparents were close by to help me as well."

Times were often hard, he hints, especially with the extra care required by Idris. Still they wanted for nothing, he recalls.

"What I'm most thankful for is when I turned 16, most people I knew in my neighbourhood were leaving school so they could go to work and bring home money for their families. My mum made me stay in school. She made sure I had all the opportunities to go to university and make a life for myself. She never allowed me to worry about money. It was all about me. I respected her so much for that. The hard work and my sense of motivation all comes from her."

He had to battle to make Britain's team for the Olympics. Luol Deng of the Chicago Bulls will be its unquestioned star with others revolving in his orbit. It is no easy task, Achara affirms. Two years ago, in the Italian league, he was the leader of his team but last season, in the superior Spanish league, he flourished as a domestique. In the GB training camp, it became an undoubted virtue.

"I feel more comfortable being that role guy," he confirms. "Changing the energy of the game, doing the dirty work that others don't do. I enjoyed it. And the fans embraced me for doing what I do. I'm very comfortable with it.That's something now I feel is good for my career. It's not a bad thing. I'm not dropping my goals. I just feel it's better for me."

Much faith has been placed on a British success at the Olympics to advance the sport and, to borrow London 2012's mantra, to inspire a generation. Twenty years ago, Barcelona's Games – and the legendary United States team of that year – sparked what has become a golden era for Spanish basketball.

"Even now, when I was in Barcelona last season, people still remember '92 like it was yesterday," says the former Falkirk Fury player. "It was a phenomenal performance from the Dream Team. You still see posters of those guys. I'm sure with the funding and all the hard work they've put into the Games, we'll see benefits."

GB remain long shots for glory after failing to get out of the first round at last year's EuroBasket in Lithuania. Little is expected, especially with the might of Spain and Russia in the same group.

"When you play on the Olympic stage, you're up against the best," Achara adds. "But we have to find the confidence to get a couple of early wins and get going from that. I really believe that with the talent we have, we can make the quarter-finals. But it's about getting that [talent] to work as a team. That's the hardest part."