Tim Cahill

The Socceroos superstar opted to leave Melbourne City earlier this month with a view to earning suitable game-time to press his case for a spot on the plane to Russia. Cahill's decision has been well documented but his next move remains unclear, with speculation linking him with clubs in USA, Asia and the Middle East. The 38-year-old could be a huge influence in Russia, but given his age, needs to play at club level frequently for the next six months.

Apostolos Giannou

The big striker is another player who could provide an X-factor, ala Josh Kennedy at the 2006 World Cup. Giannou earned five caps under Ange Postecoglou but hasn't played internationally since the 1-1 World Cup qualifier draw with Japan in October 2016. His lack of game-time with Guangzhou R&F hasn't helped his cause, although he did return late in the 2017 season with a brace, but the new Chinese regulations on foreign players means opportunities will be limited for him.

Jordan Lyden

The Perth-born 21-year-old has been in and around the Aston Villa first-team over the past 18 months but isn't currently a first-team option with the side pushing for promotion in England's Championship. Lyden is a talent, but as a defensive midfielder, has plenty of competition for a Socceroos spot (including team-mate Mile Jedinak) but may be a project player for the new boss given his promise.