The quartet, who were not offered new contracts by the Roar, comprises of Manuel Arana, Cameron Crestani, Joey Katebian and Nathan Konstandopoulos.
It follows the official confirmation last night that star striker Jamie Maclaren is leaving the club, with Borello's new club, 2.Bundesliga's FC Kaiserlauten, still favoured to sign the 23-year-old.
Meanwhile, Roar club legend Broich announced his exit from the three-time A-League champions in April.
"We’d like to take this opportunity to thank Manuel Arana, Cameron Crestani, Joey Katebian, Nathan Konstandopoulos, Jamie Maclaren along with German marquee Thomas Broich for their contribution to the Brisbane Roar," Managing Director Mark Kingsman said.
"On behalf of the club, I’d like to wish them all the best for the future."