Barnsley boss Simon Davey has accused referee Andy D'Urso of failing to protect his players after Iain Hume was left with a fractured skull at the weekend.
The Barnsley striker is currently being kept in a high dependency unit following emergency surgery, after being caught by a challenge from Sheffield United captain Chris Morgan.
Hume felt groggy after the game at Oakwell and his condition deteriorated as the weekend progressed.
Davey is facing a possible FA charge following an outspoken assessment of D'Urso's performance, but the Tykes chief has told Sky Sports News that his words were a response to the official's failure to punish Morgan accordingly.
"Myself and my assistant manager approached him (D'Urso) at half-time and felt he hadn't protected the player and a yellow card wasn't sufficient," he told Sky Sports News.
"He thought it was sufficient which to me was making light of the situation. We now have a player who is in hospital with a fractured skull.
"It's a life threatening situation. We didn't get the protection the player needed.
"I'll probably end up on an FA charge for remonstrating over another incident but I felt the referee hadn't protected the player before."