He said: "Offensively, we have to, and we will, improve. We are still quite early with the new trainer, but there are some positives. But, overall, we're really disappointed with the zero points."
The attention, therefore, immediately turns to this weekend's assignment, where we welcome Nottingham Forest to Old Trafford for a 17:30 GMT kick-off on Saturday 7 December.
"In the end, we are Manchester United," De Ligt continued. "We lost again and, yeah, it's easy, it's not good enough.
"So, we know that, we will work hard. We have to improve, and in two days or three days is the next game, so that will be a really important one again for us, to show again what we learned from this game and get the three points."