Asked if it could backfire, Mourinho said: "Yeah".
"We don't have a match in two days or a reason to think about another match".
They remained in a spine of a team that showed five changes yet still did not include Paul Pogba, a player that was the most expensive in the world two years ago at £89million, or Alexis Sanchez, the Premier League's highest-paid player.
"I didn't like the game", said Mourinho.
Without pressure they don't perform well, so what can I lose?
However, Lukaku has backed his manager's recent claims that the squad is not strong enough to win major titles, following their exit from the Champions League this week.
But Matic calmed the nerves around Old Trafford seven minutes from time when he stole in to nod Ashley Young's teasing free kick into the net.
Mourinho had used his pre-match press conference on Friday to launch an impassioned defence of his reign as United manager, in which he had hinted broadly that a number of his players had not been performing consistently this season - with only Lukaku and Matic singled out for praise.
"When the sun is shining and you win matches, every player is a good player and is confident to play".
Shaw has struggled to stay in Manchester United's team despite impressing on occasions, and has been subject to regular public assessment from Mourinho - both good and bad.
"I had to change one and I chose Luke because at least Antonio defensively was capable of good positioning". And that is an example of personality. "But when you play bad you must have that personality that a kid of 20 years old has - and some of the others didn't have". He was not afraid to play. He is the player that made mistakes, passed the ball so badly tonight, lost so many passes but had the big personality to cope with the mistake.
"But to feel not comfortable to play - ´Please Mister, take me from the pitch.´ I felt that". I would only have one more change available to make in 90 minutes.
Earlier, Spurs proved they can thrive without Kane as Eriksen's double either side of Erik Lamela's second goal of the season sent them into the last four. "Of course we were very sad after the game".