The draw for the third round of the Carabao Cup will be made on Thursday evening, live on Sky Sports.
The clash between Liverpool and Chelsea is, without doubt, the headline clash of the third round, ensuring that at least one big English club will bow out at their first hurdle this year.
Lampard, the former Chelsea and Manchester City player, will get a tough test at Old Trafford in his first season as manager with the Championship side.
They are scheduled to host champions Manchester City the following Sunday (October 7), but this game will now come after a midweek fixture in the Champions League on either October 2 or 3.
Third-round ties are to be played during the week commencing Monday 24 September 2018. Mourinho and Lampard won the 2005 trophy together with Chelsea.
The two sides met in the FA Cup in 1994 and faced off in League 1 in the 2009/10 season, with the Canaries winning all three.