Adelaide-born Agostino, 31, returns to Australia after spending the past 15 years playing in Europe, mainly with TSV 1860 Munich in Germany.

Agostino, who has UEFA Cup and UEFA Champions League playing experience, made 20 appearances for Australia since making his debut against Chile in 1996. He has scored nine goals for his country.

Adelaide United interim coach Aurelio Vidmar, who took over from John Kosmina this week, believes Agostino's inclusion will significantly bolster United's firepower for the next A-League season, starting in August.