Manchester United boss Sir Alex Ferguson was surprised to receive a Premier League letter asking him not to discuss the England manager's position.
Tottenham's Harry Redknapp is seen as the favourite to replace Fabio Capello, and Ferguson has described him as "the best man" for the job.
"You can't believe [I've been sent a letter], can you?" said Ferguson.
Asked why he received the warning, he said: "I've absolutely no idea. I'm not supposed to discuss it."
Ferguson is among a host of Premier League managers to have backed Redknapp for the England job.
"There is no doubt Harry Redknapp is the best man," he said last month. "He has the experience and personality and the knowledge of the game. He has changed the fortunes of every club he has been at."
While the Football Association insists it has not spoken to any potential candidates to replace Capello, it intends to make an appointment at the "back end of the season".
Redknapp admitted he is "flattered" to be linked to what he regards as the "ultimate job for an Englishman".