Neill Collins has been sacked as Barnsley head coach with one game remaining in the League One season, and Martin Devaney appointed caretaker coach.
The Reds had taken nine points from their previous 11 games, with the gap between them and the teams outside the play-off places shrinking from ten points to one.
They will qualify for the play-offs if they win at home to Northampton Town on Saturday, with a draw or loss potentially enough depending on other results.
A club statement read: “Collins was appointed last summer and despite several positive spells throughout the season, recent results have left the board of directors feeling that a change is needed.”
Director of Football Mladen Sormaz added: “Neill has been extremely professional throughout the period with which I have worked with him, he has done everything he can do push the team in the direction we all want Barnsley to go. He has conducted himself with professionalism and commitment throughout the period I have worked with him. However, with a crucial season conclusion ahead of us, we feel that now is the right time to make a change. We thank the fans for their continued support and urge you all to back the team this Saturday against Northampton. We will update supporters in the coming days”.
