While not featuring in the plans of new Roar coach Robbie Fowler, the 21-year-old - who is managed by Socceroos great Craig Moore - caught the eye of Tony Popovic.
And he will have a point to prove in the west as he comes into the orbit of a coach renowned for bringing out the best in his charges.
D’Agostino scored once in 17 appearances last season - 11 of which were off the bench - and is considered a work in progress.
Having joined Brisbane in 2015, he made a total of 35 A-League appearances, scoring three goals, and the expectation is that Popovic may find the key to unlocking his potential.
Olyroos coach Graham Arnold is an advocate, with D’Agostino netting a double in the 2-2 draw with Korea Republic back in March which helped propel Australia into the final phase of Olympic Games qualification to be held in Thailand in January.
D’Agostino’s first hit-out for the Glory could come against touring Premier League heavyweights Manchester United at Optus Stadium on July 13.
He will be competing for game time with the likes of Andy Keogh - who scored 15 goals from 28 games last season - and fellow new arrival, marquee Uruguayan marksman Bruno Fornaroli.
