Brentford boss Uwe Rosler was left disappointed with his side's display in their 2-0 defeat at Sheffield United on Saturday.
Danny Wilson's first competitive home game in charge of the Blades ended in success as second half strikes from Jordan Slew and Richard Cresswell secured victory.
And Rosler said: "For some reason we started slow. I think a lot of my players have not played on that level before, in a stadium like this in front of a full house.
"It was the second game of the season, with big expectations and we froze a little bit.
"We didn't have the energy and intensity that we normally have in our pressing. We were reacting instead of acting.
"I want to let my team act and get on the ball and keep control by having the ball and playing the right way. We started to do that in the end but the game was over then."