Leeds have been left with just two senior defenders after Liam Cooper and Stuart Dallas were ruled out until after the New Year.
Marcelo Bielsa's side are second in the Championship but will likely have to go through the grueling festive period with four of their most important defensive players on the sidelines.
Cooper picked up his knee injury during the win against Sheffield United and underwent surgery on Wednesday morning.
His treatment was overseen by knee surgeon Professor Moriani in Rome and he will begin rehabilitation work immediately.
Club captain Cooper is expected to be out for the next six weeks.
Dallas, meanwhile, sustained a fracture to his foot and will be out for between a month and six weeks.
The Northern Ireland international has been filling in at right-back in the absence of Leeds' preferred options in that position, Luke Ayling and Gaetano Berardi.
Berardi was ruled out for four months towards the end of October with a hamstring tendon rupture, while Ayling recently began rehabilitation on his own knee ligament issue.
He was not expected to recover before the New Year, although there is hope he may be back in contention just after Christmas.
As it stands, young midfielder Jamie Shackleton would be the most likely candidate to fill in at right-back, having featured there earlier in the season.
Finnish defender Aapo Halme, 20, replaced Cooper in the game on Saturday.
Leeds take on QPR and Bolton over the next two weeks before a meeting with promotion rivals Aston Villa.