Fulham fear Simon Davies won't be available for their Europa League kickoff.
The Wales international is suffering from a stress fracture in his foot and sat out of the last five games of last season.
The 29-year-old had hoped to be fit in time for Fulham's first European match on July 30.
However, he will miss their pre-season tour of Australia.
"It was better he stayed back to work on his recuperation," said boss Roy Hodgson