Sydney coach Frank Farina confirmed Antonis wants to stay at the club but is unsure of the potential legal ramifications.
"That's still a bit of a curved one. He supposedly has signed a contract with Parma but he wants to stay now," he told The Daily Telegraph.
"Can he get out if it, or can he not? At the moment I'm not 100% sure."
The injury has proven to be the reason why the youngster has questioned the move to Italy, according to Farina.
"He was captain of the U20s and going to Parma, the world was his oyster," Farina added.
"All of a sudden he tears a quad, he's a way off being fit, and no-one from Parma has rung him."