Leeds have confirmed that winger Ezgjan Alioski will miss the remainder of the season with a torn meniscus.
The Macedonia international was forced off after just 12 minutes of their 2-0 defeat at Brentford on Easter Monday.
Alioski is due to have surgery, ruling him out of the final two rounds of Championship games and the play-offs, should Leeds be involved in them.
"We are disappointed by the news," said the Elland Road club's director of football, Victor Orta.
"He has shown his quality throughout the year. He is a popular figure who always puts his team-mates first and sets an example for the younger players."
Alioski, who joined Leeds from Lugano in 2017, has featured in every one of their 47 games this season, scoring seven goals, and is expected to be sidelined for six to eight weeks.
Leeds are third in the table, three points behind second-placed Sheffield United, and play in-form Aston Villa at home on Sunday before travelling to relegated Ipswich on 5 May.