Marcelo Bielsa has admitted that he doesn't know whether Adam Forshaw or Tyler Roberts will be available for Leeds United again this season.
The Whites welcome Derby County to Elland Road on Wednesday evening in the second leg of the play-off semi-final clash between the two sides.
United hold a 1-0 advantage over their counterparts but have been dealt a blow with trio Kemar Roofe, Adam Forshaw and Tyler Roberts all sidelined.
Forshaw pulled up with a hamstring issue at Pride Park on Saturday before being replaced by youngster Jamie Shackleton while Roberts has missed the last three outings with an ankle problem.
Roofe - who bagged the solitary goal in Derbyshire - has been ruled out with a calf issue with United also waiting on the fitness of defender Pontus Jansson.
Patrick Bamford, though, will return to the squad after serving his two-match ban for successful deception of a match official.
"They won't be available for this Wednesday game," Bielsa said of Forshaw and Roberts.
"And I couldn't tell you for the future. In the case we have another game to play after the Wednesday game it would be difficult to have these players back.
"Roofe won't be available either. Kemar's problem is more simple than Adam's, but still he won't be available for Wednesday's game.
"(Pontus) Jansson will tomorrow try to work normally, we will see how he is."
Derby themselves have been handed a boost after striker Martyn Waghorn returned to training following an Achilles problem.
The 13-goal striker missed the weekend clash but is now hoping to make the trip to LS11 with Frank Lampard's squad.
"He broke down on Friday," Lampard said, "but he is desperate to be involved. He will be assessed up until the last moment."
Winger Duane Holmes has also been passed fit after his second half substitution against United at the weekend.
Left-back Ashley Cole (groin) could also feature after returning to training on Monday but midfielder Craig Bryson is expected to miss out along with long-term absentees Andy King (ankle), Marcus Olsson (knee), Craig Forsyth (knee) and Curtis Davies (Achilles).