The Whites have been dealt a further double blow by the news that Joe Gelhardt and Tyler Roberts will be out for a month.
Patrick Bamford, however, is back available again after his absence, leaving nine players sidelined at Thorp Arch.
"As it has been happening habitually this season, players are injuring themselves in the same position," Bielsa said during his pre-match press conference.
"So to the injury of [Patrick] Bamford and Rodrigo, we add that the injury to Tyler Roberts and [Joe] Gelhardt who injured his ankle in training yesterday and he's going to be absent for three weeks.
"Tyler Roberts a similar amount of time. The return of Rodrigo we don't have a precise date, nor Pascal Struijk. Bamford is likely to be able to play the game on Sunday."
Amid the vast amount of injuries facing Bielsa, he could give opportunities to a number of young players.
Crysencio Summerville and Sam Greenwood are among those knocking on the first team door.
He may, though, still opt for a strong line-up against the Hammers and compliment his squad with those still learning their trade in the development ranks,
Here, the Yorkshire Evening Post takes a look at how Leeds could line-up against the Hammers in cup action on Sunday...
8. Klich - AM
Will have to play a little further forward and provide an attacking spark with Leeds down on numbers. Has played here plenty before. Photo: Getty
9. Harrison - LW
A good chance to strike up some momentum after his first Premier League goal of the season last week. Photo: Getty
10. Raphinha - RW
The one man you may consider a rest for. Crysencio Summerville could come in, but you'd imagine Raphinha starts at the very least. Photo: Getty
11. James - ST
Needs must up front with injuries piling up. Bamford is back, but a bench role is more likely. Greenwood is another option here. Photo: Getty