Doncaster Rovers Belles boss John Buckley admitted his side were “psychologically battered” following their FAWSL demotion.
The Belles will play their football in the second tier of next year’s restructured Women’s Super League.
Their place will be taken by Manchester City Ladies, who currently play in the Women’s Premier League.
The decision means the Belles will not compete in English football’s top flight for the first time since the national league was created.
Chairman Alan Smart wrote in his programme notes at the weekend: “The Belles have been relegated after only 90 minutes of football.”
Buckley also pulled no punches: “The timing of the FA’s decision is embarrassing. It’s completely unprofessional.
“Why not have two banks of nine rather than eight in the first division and 10 in the second? I’m gobsmacked.
“The timing is just sickening, I’ve struggled to come to terms with it but we made sure we got all the players and staff together to discuss what to do next. The players have been psychologically battered by the news.
“My players are complete professionals and will still battle to the end, it’s just devastating for them and I’m pretty sure this decision has just come down to money.”
Despite the announcement, Belles were impressive against Chelsea in the Continental Cup on Sunday.
A fourth minute strike from Jess Sigsworth was cancelled out by Olina Vidarsdottir just before half time.
“To come out and play the way they did was fantastic,” said Buckley.
The FA said on its website it will make no further comment for the time being.
Doncaster Rovers Belles will face some lengthy trips in next season’s WSL2 with their closest rivals being Aston Villa - a 180-mile round trip.
As well as Villa, the Doncaster club will line-up alongside Durham Women’s FC, London Bees Women’s FC (Barnet FC), Millwall Lionesses FC, Oxford United Women’s FC, Reading Women’s FC, Sunderland Women’s FC, Watford Ladies FC and Yeovil Town Ladies FC.
• Doncaster Rovers Belles travel to Liverpool tonight in the FAWSL. Kick-off is 7.15pm.