The forward was omitted from the 18 for Saturday's 1-1 draw away at Stoke City and has again missed out despite Mourinho making five changes to the side who snatched a point late on against the Potters.
Matteo Darmian, Marcos Rojo, Michael Carrick, Jesse Lingard and Marcus Rashford all step into the first XI, with no Antonio Valencia, Daley Blind, Juan Mata, Marouane Fellaini or Henrikh Mkhitaryan in the starting line-up. However, Mourinho has maintained a strong look to his side, with Paul Pogba, Zlatan Ibrahimovic and David de Gea all starting.
The home side make seven changes from the side who lost 2-0 to Chelsea on Sunday, including the enforced absence of Ryan Mason, who fractured his skull at Stamford Bridge. There will be a minute's applause in the 25th minute at the KCOM Stadium as a mark of support for the No.25 in his recovery.
United hold a 2-0 lead from the first leg at Old Trafford, with the winners going on to meet Southampton at Wembley on February 26.
Hull City starting XI: Marshall; Meyler, Maguire, Dawson, Tymon; Huddlestone, Clucas, Maloney; Diomande, Niasse, Bowen
Subs: Kuciak, Robertson, Hernandez, Elabdellaoui, Weir, Goebel, Markovic
Man Utd starting XI: De Gea; Darmian, Jones, Smalling, Rojo; Carrick, Herrera; Lingard, Pogba, Rashford; Ibrahimovic
Subs: Mata, Rooney, Romero, Mkhitaryan, Shaw, Fosu-Mensah, Fellaini