In a career once teetering on the edge of collapse, his resurgence gives hope for emerging Australian prospects who hit a brick wall—Kerem Bulut, take notice.
"I was only 21, but very few clubs were willing to give me a chance, so state league soccer or early retirement loomed," Kruse told David Davutovic at the Herald Sun. "Word spread across the A-League about my ill-discipline."
In August 2008, Kruse was assaulted outside the Normanby Hotel, a location notorious for attacks on high-profile athletes, after he attempted to jump the taxicab stand.
"Robbie had a few problems and his football has suffered for it," said then-Roar manager Frank Farina via The Roar. "To make mistakes is human but to continue to do so is stupid."
He scored more goals in his first season with Victory (4) than he did in his previous three seasons with the Roar.
Kruse went strength-to-strength in his second season, dominating Roar with a brace and an assist in a 3-3 draw and coming up big vs. Melbourne Heart in a 3-1 win, while also having a four-game and three-game scoring streak.
Now a Socceroo, he was finally fulfilling his potential.
Reflecting upon his experience with Roar, Kruse told Grantley Bernard at the Herald Sun that he was a troubled kid back then.
"I didn't care I wasn't playing and there was no point playing football if I'm going to be like that," Kruse said. "My head was that far in the wrong place."
His agent John Grimaud fighting for him during the dark days, then-Victory manager Ernie Merrick's blind faith, and the love provided by Tiharny Smith, Kruse's girlfriend, created the support structure the once-troubled prospect desperately needed.
Visiting the Rheinturm was now a possibility with Fortuna Düsseldorf taking a punt on Kruse.
"Robbie Kruse is a player with great development potential but he is not a finished player," said then-Fortuna manager Norbert Meier, via FourFourTwo.com. "It is for us very important to be quick before other clubs could sign him."
Kruse spent his first season waiting in the wings, and it concerned Socceroo manager Holger Osieck, Franz Beckenbauer's assistant during West Germany's 1990 FIFA World Cup triumph.
Meier remarked via Stephan Uersfeld at ESPN FC: "It is not that easy if you fall out of a kangaroo pouch on another continent, needing to find one’s own bearing."
If there was one player Kruse needed to study, it was then-teammate Maximilian Beister.
The Hamburg loanee was tied with Sercan Sararer for most assists in 2. Bundesliga (13) that season.
The following November in the Bundesliga, Kruse outperformed Beister, back with Hamburg, in a 2-0 victory for Fortuna.
Playing as a deep-lying forward, Kruse scored and created Stefan Reisinger's goal, whereas Beister mishit five of his six shots and failed to register a single key pass.
Do you remember the anecdote about Kruse that former Roar teammate Sasa Ognenovski gave to Bernard at the Herald Sun?
"You can't walk around thinking you're a superstar at 18," said Ognenovski, who later won the Asian Champions League with Seongnam Ilhwa Chunma and became Australia's first ever Asian Footballer of the Year.
Would Kruse's success with Fortuna derail him? No.
He's matured, as evidenced by the humble response he gave to Tobias Gonscherowski, who asked the Australian if he was a star back home.
"No, football is not the biggest sport in Australia," responded Kruse via Bundesliga.com. "But I have a lot of family and friends and a lot of people who watch football and support me."
Several months later, Kathy Stone at FourFourTwo.com followed up on Gonscherowski's question.
"A star in Australia is someone like a Harry Kewell, a Tim Cahill or a Lucas Neill," Kruse said. "I’m just a footballer who comes from Australia."
"You look at all the best players in the world and they're very confident," Kruse told Nike Australia. "I try to be no different in expressing myself."
With lesser teammates, Kruse has scored and created 11 league goals compared to David Silva's 12.
"One or two newcomers haven't quite delivered, whereas Kruse has surpassed all expectations," said Wolf Werner, Fortuna's sporting director, via Bundesliga.com.
Going from the outside looking in to the team's best outfielder, Kruse could play wide right or centrally, to the relief of Meier, who was attempting to plug as many holes in a team that wasn't Bundesliga standard.
As a right attacking midfielder, Kruse gave Augsburg left-back Matthias Ostrzolek a torrid time, and the Australian registered two assists.
In a Man of the Match performance vs. Hamburg, Kruse played as a nine-and-a-half behind Rafael.
The two combined brilliantly for Fortuna's extra-time win over Borussia Mönchengladbach in the DFB-Pokal Cup.
With Fortuna relegated to the 2. Bundesliga, they've taken a chance on another Aussie, this time Ben Halloran.
The former Roar player could have a Nikita Rukavytsya-like impact in Germany's second division.
Fox Sport's Simon Hill described Halloran as the "Usain Bolt of the A-League."
In the space of several years, Kruse went from being a mistake away from dropping down into the semi-professional state leagues to a €1.5 million signing for Leverkusen, who'll be playing in the most lucrative club competition next season, the Champions League.