The manager blamed back-to-back losses on nerves.
Brentford boss Uwe Rosler blamed defensive errors as they lost ground on automatic promotion in Saturday’s defeat at Carlisle.
The Bees had it their own way for much of the game but two lapses in each half were enough to seal Brentford’s fate in Cumbria.
Sean O’Hanlon’s header looped over to make it one for Carlisle before Brad Potts set up Mark Beck to score and leave Rosler leaving Brunton Park with nothing.
“We are making mistakes. The first goal came out of nothing, a header from 14 metres that should not have happened,” said the German.
“We have the ball enough, we are attacking, we need a little more belief in the final third, and we need more aggression.
“I am disappointed.”
The defeat on Saturday means Brentford face third place Swindon Town on Tuesday after back-to-back losses – a first for the Bees this campaign.
“I always said the last ten to 15 games would be decisive and we are showing too many nerves at the moment,” said the Brentford Manager.
“If we continue like this we will fall off.
“We are showing nerves, we have to keep believing in what we are doing.
“We are not performing as we can but we are still having a lot of the ball and controlling the game.”
Photo courtesy of Kjetil Ree via WikiCommons, with thanks.
Follow us @SW_Londoner