Leeds midfielders Shaun Derry and Steve Stone are in Germany to see a specialist about their injuries - which are believed to be hernia problems. Derry sustained the injury against Crystal Palace on 13 August.
"It has not been too bad for Shaun in games but it has stopped him doing certain things," Leeds boss Kevin Blackwell said.
"Steve does not have a torn groin but he has some pain in the region which suggests he has a hernia as well."
Meanwhile, Leeds have confirmed that goalkeeper Tony Warner will return to Fulham when his loan at Elland Road ends on 4 September.