Accrington Stanley's second round Johnstone's Paint Trophy fixture against Tranmere Rovers was abandoned after 39 minutes due to a serious head injury to Stanley player Thomas Bender.
The 18-year-old, who is currently on loan at the Crown Ground from Colchester United, collided with Accrington goalkeeper Ian Dunbavin and Tranmere's Lucas Akins.
He was treated for 25 minutes before being stretchered off and taken to hospital.
Accrington assistant manager Jimmy Bell told BBC Sport: "He's been taken to hospital for observation.
"Three players went for the ball and they collided - no one on either side was at fault but our players and Rovers players are really shook up.
"It is a head injury and we are worried about him. We're waiting to hear from the hospital as he wasn't responding at the time."
Chief executive Rob Heys added: "He was starting to show signs of coming around as he left the ground."
Rovers were leading the tie 2-1 before the abandonment.
