Reading's Federici, Villa's Herd withdrawn from Socceroos squad
The Socceroos take on Denmark in Copenhagen in a friendly on June 2 and Oman in Muscat in a 2014 World Cup qualifier on June 8 but will be without Federici and Herd because of injury.
Borussia Dortmund's Mitch Langerak will replace Federici but head coach Holger Osieck has decided not to bring anyone in to replace Herd.
In other team news, Aston Villa-bound Brett Holman is in doubt for the Denmark match as he is awaiting the birth of his second child. A decision regarding whether or not Holman will join the squad in Denmark or Oman has not been made at this time.