Mourinho was responding to De Boer's criticism of how he is using Marcus Rashford at United.
De Boer praised Rashford after the match and said it is a "pity" the 20-year-old plays under Mourinho at Old Trafford - prompting an angry response from the United boss on Monday. He's very young, he needs games, he's so talented.
On Rashford, Mourinho added: "I try to give the best to the kid, I have to be honest and give the credit to the people of the academy that was responsible for his formation, to Mr Van Gaal who was responsible for his first season".
Rashford is set to feature in England's squad for the 2018 FIFA World Cup in Russian Federation and might be granted a more prominent role than expected as Gareth Southgate waits to find out the severity of the ankle injury Harry Kane suffered during Tottenham Hotspur's 4-1 win over Bournemouth.
Do you think Rashford deserves more game time under Mourinho? He wants to get results, ' he said on BT Sport.
After Rashford's two goals against Liverpool on Saturday, De Boer claimed Mourinho would not have the patience to allow Rashford the necessary room to develop. "You start smelling the semi-final". He was saying its not good for Marcus Rashford to have a coach like me.
'Not many were expecting you to start against Liverpool and he had a good match not just about scoring goals.
The Portuguese did not actually address that question ahead of the return leg against Sevilla, nor did he give a straight answer on Paul Pogba's availability on Tuesday.
Michael Carrick has confirmed he will retire at the end of the season. There were some times there, two or three days, when I wondered whether I would carry on playing or not; is it worth it or not?