Following the 3-0 home loss to Spurs on Sunday, Ten Hag admitted his team's mood could have been more positive.
"We are mad, mad with ourselves, especially when you lose a game like Sunday but you have to deal with it. We are mad, and from the madness we have to get motivation," Ten Hag told reporters on Wednesday.
"Always, when we are not winning we are disappointed and we are also mad with ourselves."
United are 13th in the Premier League table and following a 1-1 draw with Dutch side Twente Enschede in the first Europa League match, Ten Hag said speculation about his job was inevitable.
"This club wants to be back on top and it's a long-term target. We talk every day. Every day we evaluate and review the process and where necessary we make our decisions," he said.
"Everyone has to take responsibility and that starts with me as the manager. But on the pitch, we have leadership skills and they have to stand up.
"Every game for us is important and every opponent is 100% motivated. We have to be ready to compete and fight with them."
The Dutchman said midfielder Mason Mount, who was not part of the squad that travelled to Porto, was dealing with two injury issues and that defender Luke Shaw should return to action following the October international break.
