Most of United's good work came down that side, so maybe they had targeted Trent as being a weakness. He struggled defensively, but Dalot and Fernandes also stopped him from being as effective as usual going forward too.
That was another part of the game where Liverpool struggled to impose themselves in the way they normally would.
Their firepower has been unequalled this season - they are the top scorers in the Premier League - but we did not see too much of their front three for the first hour. Just before Cody Gakpo scored their equaliser, it appeared as if he and Luis Diaz were both about to be replaced.
That was down to United too. Their back three, or back five as it was when they did not have possession, has not looked very comfortable recently. In their previous game, against Newcastle, their midfield of Casemiro and Christian Eriksen got totally overrun.
This time, Kobbie Mainoo and Manuel Ugarte more than held their own, even against the energy that Liverpool have in the middle of the pitch.
It meant that, for long periods, United's system worked. They were nullifying Liverpool as well as finding ways to hurt them.