Cup draw pairs Chelsea/United with City
Manchester United or Chelsea will face Manchester City in the FA Cup semi-final at Wembley, with Millwall or Blackburn taking on Wigan.
United lost a 2-0 lead in their quarter-final against the Londoners at Old Trafford, with the date of a replay so far unconfirmed.
City, meanwhile, cruised through to the last four on Saturday, demolishing Barnsley 5-0 at the Etihad Stadium.
Championship duo Blackburn and Millwall will replay at Ewood Park on Wednesday after drawing 0-0 at the Den in a game the home side could have won.
Both semi-finals take place at Wembley and are scheduled to be played on April 13 and 14.
The Cup draw means a Manchester derby in the final is no longer a possibility and will leave Wigan, in the last four of the competition for the first time in their history, fancying their chances of getting through to the final against Championship opposition.