The Daily Mail says Campbell is considering taking Notts County to a tribunal to get his career back on track.
County want Campbell to sign a confidentiality agreement, he has refused to do so in case it prevents him overturning a ban on him playing for a new club.
The defender, 35, who ripped up his five-year contract with County after just one appearance, cannot play until January unless he explains the special circumstances of why he left Meadow Lane.
"I'm just fed up with it all," Campbell told ESPN Soccernet. "It might be simpler and quicker to go to a Football League tribunal next week and sort it out.
"I need a new club to make an appeal to allow me to play again, and to do that, the club would need to put forward my case in full."