Erik ten Hag:
Could afford to laugh off the "panic" surrounding last week's defeat to Brighton – but the joke is wearing thin.
These are very early days but it is hard to describe United's situation as anything other than a crisis.
Ten Hag is determined to bring his brand of football to the club and it was his vision that convinced United to choose him over Mauricio Pochettino. But he cannot afford many more games like this, with United humiliated before the half-time break.
If the players he inherited cannot fit into his system, then he will have to change the system – even if only in the short term.
Lisandro Martinez:
Signed as one of the key players to implement Ten Hag’s brand of football, due to his ability to build from the back.
But he has endured a chastening first two games in English football, which has already seen him targeted by opponents due to his height.
He will take time to get accustomed to a new league and has not been helped by United’s shambolic performances so far. But the fact that Ten Hag felt the need to substitute him at half-time was a measure of Martinez’ struggles.
Far too weak when beaten by Ben Mee for Brentford's third and it is hard to see him keeping his place for the Liverpool game.
David de Gea:
This was a horror show for the Spaniard.
Made an absolute mess of Josh Dasilva’s tame effort from distance to allow the ball to squirm through his hands and into the back of the net and give Brentford the lead.
Then, he put Eriksen under pressure for Mathias Jensen to double the home side's lead.
In punishing heat, De Gea was facing the early evening sun – but even that cannot be used as an excuse for either goal.
It was a game to forget for the goalkeeper, who had looked to have put such performances behind him after returning to his finest form last season.
If Dean Henderson were still at the club, De Gea would almost certainly be dropped.
Christian Eriksen:
Returning to the stadium he lit up in the second half of last season, Eriksen was roundly booed by Brentford fans every time he touched the ball.
And the home crowd rejoiced in seeing him commit the error that led to their second goal.
Receiving the ball on the edge of the area after a short pass from De Gea, the Dane mis-controlled under pressure from Jensen, who seized possession and fired low into the corner.
De Gea didn’t do him any favours – but he still should have done better in that situation.