Mads Roerslev admitted there was frustration inside the Brentford dressing room after defeat at Manchester United.
Marcus Rashford's first-half strike proved to be the one goal of the game, with substitute Kevin Schade going closest for the Bees after the interval.
Obviously, we are disappointed that we lost today," Roerslev told the Bees website.
We came out with effort but lacked a bit of quality on the ball, especially during the first half.
It was very frustrating to concede from a set-piece. We know that in games like this, it's the margins that decide the result. Set-pieces are a strength for us, so we're disappointed about that.
We came out good in the second half and tried to create. Sadly, we didn't get a goal.
We came here to win, and we'll take the next game as we always do and go for the win again."
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