Swansea City's top scorer – currently away on internation duty with the England Under-21s looks a likely candidate for this summer's European Championships and that should then put him at the front end of the queue for Team GB at the London 2012 Olympics next summer.
And his brother Martin – who has Cerebral Palsy – is set to make that a family double by being in the Paralympics.
"He plays in the Cerebral Palsy team," Sinclair told the Evening Post
"His left arm and his leg doesn't work as well as they should do. He broke his hip which made it a bit worse.
"He's normally everywhere, he plays defence, striker, midfielder — they play seven-a-side.
"He comes to support me, basically every game I play. We are very close and he comes to most home games and away games when he can — sometimes it's too far to travel.
"Sometimes you look at the guys and because they play so well you think, 'Is there anything wrong with these guys?'
"It's amazing when you see what's wrong with them and what they do.
"It puts stuff in perspective and if you have had a bad game and you dwell on it, I see my brother and what he deals with and it puts perspective on your own view.
"If everything goes well, he should get picked and could be playing in the Paralympics next year.
"It would be the best summer if I could get promoted with my club and win the Championship.
"I've had seven loan deals and I was fed up of going on loan and not being settled.
"When you go on loan, you're not really part of that team and you go back and you never really know what's going to happen, so I thought it was best for me to go and get some football."