Sunday's game was not three minutes old when Ten Hag's men allowed Micky van de Ven to run half the length of the pitch with ease and find the unmarked Brennan Johnson who tapped in for the opening goal. A rout at Old Trafford was on the cards.
However, Ten Hag, whose job security was the subject of speculation for much of last season, insisted he was not concerned about his status with the club.
"No, I am not thinking about this," he told reporters. "We all made in togetherness this decision to stay together, as ownership, as a leadership group, in the summer. We also knew it would take some time.
"I think we will get better. And we all are there on one page, in one boat together, the ownership, the leadership group, the staff and the players group as well. So no, I don't have that concern."
The loss left United, who finished a worst-ever eighth in the Premier League last season, in 12th place after six games.
It was their second consecutive 3-0 home league defeat after they lost to Liverpool on September 1st, and thousands of fans beat a hasty exit from Old Trafford well before the final whistle.
Former United defender turned pundit Gary Neville called it a "disgusting performance."
Former Tottenham midfielder Jamie Redknapp said in the Sky Sports broadcast: "United have been so abject, no confidence, no identity, they have been playing like the away team.
"It gets to a point where you feel for the manager. He looks completely out of his depth and is struggling to motivate."
Dejan Kulusevski and Dominic Solanke also scored for Spurs, who from the start ran circles around a United side reduced to 10 men when captain Bruno Fernandes was sent off in the 42nd minute for his high challenge on James Maddison.
Ten Hag was particularly frustrated that Johnson's early goal was almost identical to one United conceded against Twente in a 1-1 Europa League draw only four nights earlier.
"We are very disappointed when you can see it again, a goal like this," the Dutchman said. "It shouldn't happen, and especially when you address it so loud and clear, how we have to deal with such situations."
