Oldham have been hit with a £100,000 bill towards a shortfall in the Football League's pension scheme.
The figure demanded dates back to the club's time in the Premier League 20 years ago.
The Boundary Park outfit are set to lose £250,000 per-season in television monies over the next three years and has a £130,000 fall in season-ticket revenue. Also, the loss of Sheffield Wednesday, Sheffield United or Huddersfield, Rochdale and Chesterfield from npower League One could hit the club to the tune of £600,000 at the turnstiles.
"We face having to find over £100,000 which has come as a great shock as it goes back over 20 years and relates to previous managers, directors and staff," Simon Corney, chairman, told Oldham's official website.
"It amounts to one quarter of the money raised so far from season-ticket sales and is massive blow to deal with.
"The letter has shaken me and it will have a big impact having to find this sum of money. The agreement was entered into when Latics were in the Premier League and it concerns me greatly."