Aston Villa chairman Doug Ellis cited the busy Christmas post for the lengthy delay of last night's quarter-final at Villa Park.
Thousands of fans from both clubs were left queuing outside the ground in bitterly cold conditions.
Ellis said: "We sell tickets through the Ticketmaster agency and there were several thousand for Villa and for Liverpool. Ticketmaster have been saying there is no point in putting the tickets in the post because the fans will not get them because of the Christmas post.
"They have been saying 'get down to Villa Park and the ticket office and pick them up' - but unfortunately something like 17,000 turned up to try and get into the ground at 20 to eight this evening.
"Therefore we couldn't serve them in time for the kick-off."
Villa media relations officer Phil Mepham said: "There were up to 6,000 tickets sold by Ticketmaster and it was decided because of the Christmas post not to put them out in the post.
"A fair amount of those - we don't know the exact number at the moment - were told to pick them up at the collection window and that's caused congestion because everyone has turned up together.
"The Police then decided that we couldn't kick off because of safety."
The game eventually kicked off at 9.05 - 80 minutes after the original starting time.
LEAGUE CUP SEMI-FINAL DRAW
Manchester United v Blackburn Rovers
Sheffield United v Liverpool
Ties to be played on January 6th and 20th
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