United were beaten 3-0 by the Reds at Snapdragon stadium.
Ten Hag said: "There were mixed feelings, I would say. I think I have seen positive bits, but the way we concede goals, we are, of course, not happy with it. Of course, Liverpool are a very good side. They are very aggressive, and they have lots of goalscoring abilities, so they did very well. But the way we conceded, we are not happy with it.
"As I said, I think there were good bits, and the first goal is always very important. I thought Liverpool played very well, but they were also very efficient.
"The group and staff, everyone has done a great job. It's always tough at the end of such a tour, but we are really pleased with all the effort they put in. We came together, we worked on our game model, and now we have to fly back and we have to recover, because it's tough. Especially the last days, and then such a tough game at the end, but you learn a lot about your team. Now we have to recover, and then go to prepare the next game, and it is a big game."
On young left-back Harry Amass, he added: "I said already the other day: there is a potential, but he has to improve. But I think in the last 12 days here in the tour, he has made big steps. He was really tested in defending, and he made a step forward, but there is still a long way to go."