Uwe Rosler watched his Brentford side let slip the lead to go down 2-1 at Doncaster and said they must stop being "too nice".
Brentford dominated much of Saturday's League One visit to the Keepmoat and carried a 1-0 lead into the break after Jonathan Douglas had clipped home Adam Forshaw's through ball.
But a 25-yard stunner from Rovers winger David Cotterill levelled the game with 15 minutes to go, sparking Doncaster to life, and the hosts sealed the win with a powerful header from Billy Paynter.
Rosler said: "At the moment we are too nice. This is why experienced players who have been around the block are taking advantage of us.
"We need to be more ruthless, more cynical and more aggressive in those types of situation. The more we are talking about the away form, the more it is becoming a problem. We won't be talking about it now.
"I'm getting sick and tired of it. I would like to win 1-0 and play bad. We had plenty of chances to get the second and we were defensively sound for most of the game, so it went to plan in a lot of ways. But I'm speechless, we've controlled the game and lost."