Manchester United head into the clash at the KCOM Stadium with a healthy advantage after last week's 2-0 first-leg win at Old Trafford.
Mourinho has made five changes for tonights match, bringing Matteo Darmian, Marcos Rojo, Michael Carrick, Jesse Lingard and Marcus Rashford in to the starting XI.
Manchester United boss Jose Mourinho is expecting a tough clash against Hull
And the United boss is expecting a difficult test against Marco Silva's side.
"Normally there is an immediate effect of a change of manager," Mourinho told MUTV.
"It brings something positive in terms of motivation to the players.
Man United stars forced to drive down a farm track to get to training
Thu, January 26, 2017
Manchester United players were forced to take a detour down a tiny farm track in order to reach their Carrington training base on Wednesday
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Manchester United stars were forced to take a detour to training on Wednesday
"But I know Marco well. He is a good coach, he is going to effect the team and improve it.
"I know that they are playing better. I know that they are bringing some players in who I already know that have played in Portugal.
"So I think it's going to be difficult, they have the dream and the dream is alive."