Mourinho described Paul Pogba as "a monster" after the unsettled Frenchman responded to being captain with a dominant performance in United's 2-1 win. "I think football is changing and probably football managers should be called head coaches".
"We have big coaching staffs and I think we are more the head coach than the manager".
"It will be a hard season for everybody, not just for us", said Mourinho. "We have to wait until the end of November to understand if we can fight for the title".
And when Amartey was substituted, it didn't get much better - Luke Shaw completely lost Rachid Ghezzal for his goal in the 83rd minute, while Ricardo Pereira was ineffective right-wing and only started to look like a Premier League player when switched to right-back.
"It's time just to say "tomorrow we have a Premier League match" and we have to play to win it".
Yet the fall-out from a disappointing transfer window that saw United fail to sign the central defender Mourinho was demanding was still the subject of debate as he was asked about the club's lack of summer spending.
If he remains at Old Trafford beyond the 31 August European transfer deadline how do the club, and Mourinho, manage the World Cup-winning star? They certainly seem very unsure of the players he has brought in before - [Eric] Bailly, [Victor] Lindelof.
'Of course, we have second or third choice in case he is not confident or for some reason doesn't want to take it.
Mourinho also confirmed Pogba had his blessing to take the penalty after what appeared to be a disagreement with Alexis Sanchez. "We will have the same players, the injured players are not going to be back", said Mourinho. I was among the names as well.
Claude Puel, the visiting manager, said: "It was a shame to concede this goal at the beginning of the game".
The interior designers recruited into The Theatre of Dreams have obviously been more productive than chairman Ed Woodward this season in giving United a makeover, and the results are sure to make the rest of the Premier League green with envy, radiating class and sophistication. I need more changes. They were trying to get it done before the World Cup but before a ball was kicked they had it done. "It's a good way to start the Premier League".