Portsmouth registered defender Dusko Tosic has seen a move to Swansea City blocked by the FA.
The Daily Mail says the Serbia defender was signed outside the January window as a free agent to play in the FA Cup against Southampton, but the Premier League decreed that Portsmouth could not register any more players due to their financial situation - so withheld his registration to play in league games.
The FA say he cannot now sign for Swansea because, due to the FA Cup game, he is registered as a Portsmouth player.
The player's agent is considering the next step, which may be legal action.
A source said: "They are messing with a player's life here."