Alex Ferguson considered invoking a little-known rule so that Manchester United could avoid a replay with Tottenham Hotspur if their FA Cup fourth-round tie ended in a draw, British media reported today.

Ferguson told reporters he had learnt of Article 11a which allows teams to agree to play for an extra half-an-hour to settle the match and avoid a replay.

United are in the hunt for four titles this season, have 11 players out injured, face a congested fixture list and would not want to play an extra match.

However, the law has to be invoked within seven days of the draw being made with the agreement of both clubs so Ferguson's idea did not come to fruition. The draw for the fourth round was made on January 4.

Replays have been part of the FA Cup since the competition started in 1871-72 but Ferguson was only recently alerted to the rule.

"I had never heard of it but it's in the regulations," he said. "The criticism would be that we're not adhering to the principles of the FA Cup or the spirit of it, but why have the FA got it in there? We will investigate."

An FA spokesman said: "The rule exists primarily to help smaller clubs in the preliminary rounds settle a tie after a one meeting so they can avoid lengthy journeys or suffer financial costs.

"It makes sense for the rule to govern the matches in the preliminary competition.

"We have checked through the history books and no professional club has ever tried to invoke the rule because replays can be so lucrative and are such a rich part of the tradition of the FA Cup."

It is not the first time that Manchester United have been involved in an FA Cup controversy. The club, who have won the competition a record 11 times, failed to defend the trophy in 1999-2000 due to a commitment to take part in the FIFA Club World Championship in Brazil.