With the Europa League final against Ajax looming large on Wednesday, United will field an experimental side for Sunday's Premier League dead rubber against Crystal Palace.
Ajax entered the competition after being knocked out in the Champions League qualification stages by FC Rostov, but Mourinho thinks there should be no second chances in Europe.
It will not just be kids playing against Palace as Mourinho confirmed £89million signing Paul Pogba will start after missing the past two matches following the death of his father Fassou Antoine at the age of 79 last Friday.
"They're nice words and now I need to prove that he's right", he said.
Premier League giants Manchester United are reportedly keeping a close eye on a certain goalkeeper should David de Gea leave Old Trafford at the end of the season.
"It's frustrating for me". I don't lose time. "I think a European team shouldn't play two European competitions in the same season".
If Palace beat United - a feat they have not managed in the league since 1989 - and other results go their way, they could rise to 11th in the table and net £19m in prize money.
"So half of the year we spent together and that is only possible when the spirit is incredible".
"It would be wrong for me as a manager to jeopardise anybody that you want to pick for that football match". One in the middle of a good structure, an experienced structure, I think yes. Tells (Wilfried) Zaha to go slow, leaves (Christian) Benteke at home.
He added: "We have a few on crutches but everyone goes". The number of young players set to feature is a byproduct of the injuries the Red Devils are dealing with, as Mourinho is even having to rest several squad players for the Europa League final.
The Belgium global was substituted in the 75th minute and had a brief chat with Mourinho before walking straight down the tunnel with what appeared to be a muscle problem.
With the club's focus centred on next week's Europa League final against Ajax, Mourinho is expected to give run-outs to as many as five raw talents at Old Trafford this weekend: Josh Harrop, Zak Dearnley, Matty Willock, Scott McTominay and Demetri Mitchell.
"He says it was a minimal thing but minimal can be a big thing". With the Ajax game in mind, Mourinho said he had a "little bad feeling" about the injury.