It was originally expected the 36 year old would sign a five-week contract beginning after this weekend to coincide with regular goalkeeper Danny Vukovic's five-week ban for striking a referee.

The Mariners will hold a press conference to officially announce the signing of Bosnich on Wednesday.

Vukovic said Bosnich, who has been training with the Mariners for the last month, had been helping him overcome his issues.

"He's always full of advice, not only with goalkeeping but in life in general," Vukovic said.

Last month Bosnich impressed during a trial with the Mariners in the A-League pre-season cup, including a penalty stop in a 3-0 win against Sydney FC.