The champions, the brand of football they're playing and that will hurt Man United supporters.
United initially showed promise in an even first half with Brazilian Fred finding plenty of space they and should have taken the lead through Romelu Lukaku after he was presented with a gift of a back-pass from Danny Rose.
United have lost two of their opening three games of the season and conceded six goals in the last two games.
The defeat for Mourinho is the most lopsided home loss in his career and makes Tottenham the first visiting team to score three goals against Man United at Old Trafford under the Portuguese manager.
Writing in his column for The Times, Souness said: "Chelsea's failure to defend their title or finish in the top four last season provides a cautionary tale for Manchester United in the current campaign".
In the first half, zero corners, zero lateral free-kicks, zero frontal free-kicks. We were not unsafe enough, because Sevilla deserved to win the match.
China trade dispute escalates
And as China has vowed to retaliate further, Trump has threatened to target all $500 billion in goods the United States imports. The U.S. and China imposed fresh, previously announced tariffs on each otherâs goods in the middle of trade talks.
"You see a lot of things in the media about what our dressing room is like but we have a really good spirit and a good group of lads", he added.
Asked about the thousands of empty seats at the final whistle, Mourinho replied: "I would do the same (leave early) losing 3-0, taking two hours from here to the centre of Manchester, because is where I live and after matches it takes two hours, so keep trying, keep trying, keep trying".
"I felt Tottenham felt it, I think we were feeling that too".
But Martial is not to Mourinho's taste and although he can no longer replace the forward, the Manchester United manager still wants the player sold before the transfer window across Europe closes on Friday. There is a blame game going on here and the players do not look like they want to play for him.
In the other dugout, Spurs haven't brought anyone in, but there were no complaints and they are united.