Nevertheless, the Reds earned a point on the road, and hung in despite Brentford's lengthy spells of control and numerous attempts on goal.
And there were some positives to reflect on, namely Mason Mount's first goal in a United shirt and a resolute performance from Andre Onana between the sticks.
Raphael Varane and Victor Lindelof defended stoutly before they were forced off the pitch with injury, and Lisandro Martinez made a welcome return from a near two-month lay-off.
But who will you vote for in our poll to decide which player should be named Man of the Match?