A-League newcomers Western United believe they have signed three of Australia's most promising youngsters.
Pasquali is a highly-rated midfielder currently playing with Dutch giant Ajax, while Stamatelopoulos (Adelaide United) and Pierias (Melbourne City) will leave their current A-League clubs.
Pasquali, who made two appearances for Melbourne Victory in 2016 before departing for Ajax, has represented Australia at under-20 level.
"Already being part of European football's greatest school in Ajax, we are excited to have Seb bringing his learnings and to push through to playing first team football and continuing his rise," Western United assistant coach John Hutchinson said via a statement on Wednesday.
"Stama is a very exciting forward who has already tasted A-League football so we believe he will develop into a mainstay of our attacking third for many seasons to come.
"And in Dylan we see a player who can slot into anywhere on right side of the pitch, so versatility is a trait we want in all our players."
United have previously announced the signings of Greek international Panagiotis Kone, Socceroo Josh Risdon, Sydney FC defender Aaron Calver and Australian age group representative Connor Chapman, who will head home from South Korean powerhouse, the Pohang Steelers.