The draw for the third round will be made at 14:40 GMT by former Tottenham Hotspur captain Ledley King and former Bolton Wanderers midfielder Fabrice Muamba.
The number 25 ball will represent the Reds in the proceedings and ManUtd.com will publish the outcome as soon as it's confirmed. The third-round ties will be played over the weekend of 5 and 6 January 2013.
United, who last won the trophy in 2004, won away at Manchester City in last year's third round, but bowed out in round four after a 2-1 defeat to Liverpool at Anfield.
21 Leeds United
24 Manchester City
28 Newcastle United
39 Tottenham Hotspur
Ties to be played over the weekend of 5/6 January.