Keeper Nathan Coe has been drafted in from Denmark to make up the numbers - but it still leaves a reduced-size squad looking threadbare, sparking new speculation that Brett Emerton and Harry Kewell may be called up.

Both were given a pass by Socceroos coach Holger Osieck to appear in the blockbuster A-League opener between Melbourne Victory and Sydney FC.

at the time he insisted there was no chance either would be called up for the Oman clash if they came through the interstate derby.

But with the Socceroos squad now down to just 18, Osieck may revisit that pledge.

Emerton is in peak fitness after a full pre-season and early season matches for his former club Blackburn Rovers in the English Premier League prior to joining Sydney FC.

Kewell has yet to prove himself after a near-six month lay-off since his last competitive match for Galatasaray before he finally agreed terms with Victory.

But now if both pull through this Saturday's match, Osieck may decide to call them up to strengthen his thinning side.

Everton today confirmed Cahill needed to recover from his latest injury.

"Tim played through the pain barrier on Saturday against Liverpool but the scan showed that the best course of action now is rest and rehab," the club's head of medicine Danny Donachie told evertonfc.com.

"Tim is disappointed but it is a straightforward decision because he would not be fit enough to play in the games in Australia."

The FFA also confirmed Schwarzer's back injury had flared up again, forcing his withdrawal.

"Two weeks ago Schwarzer injured his back whilst playing for his club, Fulham FC, and reinjured it again during the warm-up for his match against Queens Park Rangers yesterday," said an FFA statement.

"Cahill sustained a leg injury playing for his club, Everton FC, against Manchester City on September 24 and, although he was cleared to play on the weekend, exacerbated the injury during the match against Liverpool FC on Saturday.

"After consultation with the players, their respective clubs and the Qantas Socceroos medical staff, Osieck has decided that both players would not be required in camp."