Derby County first-team coach Paul Simpson has confirmed that forward Mason Bennett will be sidelined for up to eight weeks with a knee injury.
The 18-year-old suffered the problem last week during an Under-21 victory for the Rams against West Bromwich Albion.
Bennett scored the only goal of the game before he was stretchered off the pitch with the injury.
Derby continue their Championship campaign on Saturday when they travel to Elland Road to face Leeds United.