Huddersfield midfielder Aaron Mooy is blocked from their FA Cup tie with Manchester City.
Mooy is forbidden by the FA's own rules for the competition, and the player's ineligibility is nothing to do with City.
The FA's rules state “The association will not give permission for players on loan or work experience to play against the lending club".
Many fans pointed out that Sanchez Watt played against his club Arsenal in the FA Cup while on loan at Leeds in 2011, after the Gunners gave permission for him to do so.
But that was the last time anybody played against the club owning his registration - the FA changed the rules in the 2011-12 season.