Vidosic was hailed as 'Brisbane's brains' for his tactical work as Ange Postecoglou's assistant to help Roar to two A-League Championships in 2011 and 2012.
 
And the move to Sydney sees him reunite with Farina after the pair were at Queensland Roar between 2006 and 2009.
 
“I’m delighted to be joining Sydney FC and to be working together again with Frank,” said Rado.
 
“There is a great potential at Sydney FC and I hope to work extremely closely with the players and help them make the most of their ability.
 
“We have a very strong and talented squad and I expect us to be challenging for honours this season.”
 
Farina's experience of Vidosic's knowledge led to him to make the approach for his services.
 
“It’s great to be able to bring Rado to Sydney FC,” said Farina.  “Having worked with him before I know he is a first class coach and will give the squad an extra influence.
 
“He has a real analytical and tactical brain and is very experienced in bringing the best out players."
 
Chief Executive Officer Tony Pignata added: “Rado has a great track record and knows exactly what it takes to win an A-League Championship.
 
“We are delighted to have him on board and I believe his knowledge and tactical expertise will help Sydney FC achieve success on the pitch this season.”
 
Vidosic will take care of first team training, with Steve Corica returning to youth league coaching duties after the departure of former NYL coach Brian Dene in the off-season.