Barnsley's League One game with Burton was postponed after a spectator fell seriously ill shortly before kick-off.
The two teams had made their way out on to the Oakwell pitch for the 3pm kick-off but they soon returned to the dressing rooms while medical treatment was given to the fan on the side of the pitch.
An air ambulance landed on the playing surface at 3.30pm and the decision to call off the game was made soon after.
Barnsley tweeted: "Due to the circumstances the match has been postponed.
Barnsley Football Club will look to provide further update when appropriate to do so."
There has been no updates on the condition of the supporter.