Leeds United duo Tyler Roberts and Stuart Dallas are doubtful for this weekend's Championship clash with Ipswich Town at Portman Road.
The Whites travel to Suffolk in the final game of the campaign ahead of the end-of-season play-offs.
United require just a point to secure third position in the table and set-up a semi-final clash with sixth spot, which remains a three-way battle between Derby County, Middlesbrough and Bristol City.
Leeds will be without striker Patrick Bamford following his two-game ban after he accepted a charge of "successful deception of a match official" in the 1-1 draw with Aston Villa last weekend.
Barry Douglas and Gjanni Alioski have both already been sidelined for the remainder of the campaign.
Bielsa also revealed that there were doubts over Tyler Roberts (ankle) and Stuart Dallas (knee), with the pair both fighting to be fit for the trip to face Paul Lambert's side.
"(Patrick) Bamford won't be available," Bielsa revealed.
"We have a doubt with Tyler Roberts, and with Stuart Dallas. Of these two doubts we may have a positive outcome with Dallas. With Roberts it is a little bit more complex."
Asked whether he was worried over the duo's fitness for the play-offs, he said: "No, because they're not serious injuries."
Kemar Roofe is also expected to return to the matchday squad following his absence with a hip injury for the visit of Dean Smith's side last Sunday.
"He is completely fit," Bielsa added.
"But we can't ignore the fact that he has spent some time without playing 90 minutes."
Ipswich are facing a headache with a number of injury concerns over forwards Will Keane and Ellis Harrison while Collin Quaner is expected to step in.
"Will (Keane) is out," Lambet said. "Ellis (Harrison) has just started back training so it is too early for him. Collin (Quaner) will be okay, so we'll see how we are tomorrow."
On Leeds, he added: "I think they've got momentum, they've got a manager who is relentless. If you don't match there desire then it's going to be a difficult game. They're one of the best teams in the league."