Watford head coach Tom Cleverley told BBC Three Counties Radio his side must improve their away form if they are to challenge for promotion.
The Hornets fell to a seventh away defeat of the season at Burnley - in stark contrast to their unbeaten home record.
"I think the scoreline flatters us - I've told that to the players. That could have been a lot more convincing (for Burnley) and was nowhere near an acceptable performance from us today.
"They showed more personality to play on the ball, they showed better problem-solving but, most worryingly, they ran more and tackled harder.