In arguably the league's biggest coup ever, it's believed the star keeper agreed terms with the former NSL club on the weekend and will be unveiled later this week.

It's understood that Bosnich, 37, wants to stay sharp in the off-season with a view to returning to the A-League next season.

The former Socceroo shot-stopper played for Central Coast Mariners on a seven game deal at the start of last season and his experience was sorely missed during the Mariners' subsequent A-League and ACL campaigns.

Since then, Bosnich has trained with Sydney FC but a deal for next season's A-League has so far not been forthcoming.

Sydney Olympic, coached by former NSL winning coach and Newcastle Jets boss Nick Theodorakopoulos, are home to Sutherland Sharks this Sunday at Belmore stadium.