United beat Liverpool 4-3 in the quater final at Old Trafford on Sunday, despite trailing 2-1 and then 3-2 in the game.
"If you oversee this season, we have had so many setbacks all the time," said Ten Hag post-game.
"We have players dropping out and, every time, we have to adapt. Also, yesterday, Jonny Evans, in the last minute of the training, he dropped out. Then we have to adjust to bring a player in who didn't train, didn't play for four or five weeks and he had only one or two training sessions with the team.
"And then he came in and Aaron Wan-Bissaka was playing so well, but the team adjusted also to that we had to change.
"And so we can deal better with such situations," he added.
"Where we were in autumn, it was difficult to adjust where we had all the injuries.
"So what you now see in January, February, March, we can deal better with this. And still we have a lot of injuries, but we can deal with it. We get our wins."