The talented but inconsistent youngster feels he may have turned a corner in his battle for form and fitness at the heavyweight German club
The 21-year-old has had to bide his time since signing for the Bundesliga heavyweights in July 2011, spending the following season back on loan at the Central Coast Mariners.
His next two campaigns were interrupted by injury and he is yet to make a senior Bundesliga appearance at the Westfalenstadion outfit.
However, after coming on against Liverpool in a 4-0 friendly defeat at Anfield last Sunday, the creative midfielder - a player considered prodigiously talented when he burst onto the scene in the A-League - believes his opportunity to shine may arrive in 2014-15.
"I ... played off the bench in the warm-up matches against Chievo Verona and Slask Wrocław before the Liverpool game and the coach has told me I am now more of a man than a kid," he told The World Game.
"He is happy with me and has told me I am maturing as a player. I think it's looking good. I am playing now more (in a) central midfield role and have added a bit more power to my game."
Amini is yet to make a senior appearance for the Socceroos, and while he has a number of Under-20 and Under-23s caps to his name, he has also fallen out of favour with the youth set-up.
Nevertheless, the former Blacktown City and Australian Institute of Sport man hopes to catch the eye of senior head coach Ange Postecoglou in the coming months.
"There are a few of the boys from that team now breaking through and I don't see any reason why I can't join them at some stage," Amini said.
"I am training with world class players every day. People might say 'you are not playing Bundesliga' but it's tough. The club is challenging for everything. And the competition is intense.
"Hopefully the Socceroos come calling. It's good to see Ange giving young players a go - and if I get a shot it's up to me to show him what I can do."