Leeds winger Helder Costa has been ruled out of the last four games of the Premier League season.
The Portuguese missed last week's 2-0 defeat at Brighton due to a back injury sustained in the recent draw against Manchester United.
"He won't be able to compete again this season," said Leeds head coach Marcelo Bielsa, who confirmed both Kalvin Phillips and Raphinha remain doubtful for Saturday's home game against Tottenham.
Former Wolves player Costa, who has started 13 league games for Leeds this season, was hurt in a challenge with Manchester United defender Aaron Wan-Bissaka and was forced off midway through the second half.
Phillips also missed out at Brighton due to a knock behind his knee, while Raphinha has been sidelined for three games after sustaining a badly bruised thigh in the win at Manchester City earlier this month.
Skipper Liam Cooper's return to the starting line-up after completing his three-game ban does not appear to be a foregone conclusion.
Cooper was a regular starter in central defence before his dismissal at the Etihad Stadium, but Diego Llorente and Pascal Struijk have formed an impressive partnership in his absence.
"Pascal and Llorente have shown they can live up to the level the previous people who have played in this position were playing at," Bielsa said.
"As you well know, there are other factors taken into consideration when you look at each game.
"In any case, I always consider what's best for the team and what's best for each player that participates because there is nothing more important than to favour the participation of each player."
Bielsa said he welcomed the pending return of fans to stadiums for the final two matches of the Premier League season.
Subject to government approval – due to be announced before May 10 – 8,000 fans will be allowed into Elland Road for Leeds' final home game of the season against West Brom on May 23.
"To be able to experience the fans at Elland Road in particular is an experience always worth living," Bielsa said.
"Even if the stadium will be partially occupied, it's a way to experience how the fans behave with the players.
"That's a very pleasing sensation. It's one of the prizes, not an economical prize, that is one of the most valuable things in football."
Leeds lost for the first time in seven league games at Brighton and sit 11th in the table, while Tottenham have not given up on Champions League qualification.
They have taken maximum points from their two league games under interim head coach Ryan Mason, with Sunday's 4-0 home win against Sheffield United leaving them five points off fourth place with four games remaining.
