Ken Bates put a block put on him making his 60th appearance in a white shirt as it will trigger an additional £250k payment to Derby.
"Seth is most disappointed Mr Bates has chosen to put the matter into the public domain in this manner," said Johnson's representatives.
He added: "Seth suffered an horrific injury in snapping his cruciate ligament and has undergone a number of operations, missing a huge chunk of his career as a result.Thankfully, Seth is now fit and eager to play for Leeds United."
But his Elland Road future is in doubt with Leeds seemingly keen to get a player who earns £35k-a-week off their wage bill.