Leeds United midfielder Ramon Nunez has suffered a cruciate ligament injury playing for the club's Under-21s side.
The Honduras international had been deemed surplus to requirements at Elland Road but his injury could now mean he will remain at the Championship club.
Under-21 coach Neil Redfearn told the club's official website: "It didn't look good and when a player goes down like that your initial reaction is that it could be long-term.
"If that's the case, it's a shame for him but he will be assessed as to what the extent is before we find out."
Nunez has scored one goal in 20 appearances for Leeds.