United's Argentine head coach was without the services of nine injured players for last Sunday's FA Cup clash against the Irons, Patrick Bamford finding himself back on the sidelines due to picking up an injury below his hip in training.
That meant Bielsa was without his four main striker options, Bamford out along with Joe Gelhardt (ankle), Rodrigo (heel) and Tyler Roberts (muscle).
Young Sam Greenwood started upfront against the Hammers but was then added to the extensive list after picking up an injury against the Irons.
Kalvin Phillips (hamstring), Liam Cooper (hamstring), Pascal Struijk (foot), Jamie Shackleton (Achilles) and Charlie Cresswell (shoulder) were also missing and Leeds then lost the services of Junior Firpo in the contest following a collision of heads with keeper Illan Meslier.
Firpo revealed after the game that he had felt a bit dizzy and was later feeling fine but there are concussion protocols that must be followed.
In addition to the huge amount of injuries, United's Spanish international defender Diego Llorente is suspended for this weekend's league rematch against the Irons having picked up five bookings, in addition to Roberts who is also banned but injured anyway.
That means there are doubts about 12 players and this is how Leeds could line up in Sunday afternoon's Premier League clash at the London Stadium.
1. GK - Illan Meslier
The star young Frenchman is the only Leeds player to have played every single minute of every league and cup game so far this season and eventually seemed fine after colliding with Junior Firpo last weekend. So important that he stays fit.
2. RB - Stuart Dallas
First choice right back Luke Ayling is likely to be needed at centre back and Cody Drameh has gone on loan to Cardiff City so Dallas is likely looking at another shift on the right side of defence.
3. CB - Luke Ayling
Leeds will be without the injured Liam Cooper and Charlie Cresswell plus the suspended Diego Llorente so unless Pascal Struijk is back that surely means right back Ayling playing at the heart of the defence. But who partners him?
4. CB - Leo Hjelde
This would be a big call as 18-year-old Hjelde only made his debut last weekend but the Norwegian centre-back excelled against Michail Antonio and Robin Koch might well be needed in midfield. Lewis Bate starting at CDM and Koch at CB is another option.
5. LB - Junior Firpo
Firpo was eventually taken off against the Hammers after clashing his head against Illan Meslier and much depends on his condition due to concussion guidelines but if all is well then the improving left back will surely start.
6. CDM - Robin Koch
The German international defender started in midfield last weekend and it might well be same again unless young Lewis Bate is handed a league debut which would allow Koch to play at centre-back.