Gera is the latest Fulham player to suffer an injury ahead of the Barclays Premier League clash with Portsmouth.
Gera has joined a long list of players in the treatment room after suffering a knock to his knee in training.
Andy Johnson is still struggling with his knee problem while Paul Konchesky (foot), Simon Davies (ankle), Clint Dempsey and John Pantsil (both knee ligaments) are all out.
Loan signings Nicky Shorey and Roma striker Stefano Okaka are both poised for their Fulham debuts.
Source: PA
Source: PA