West Brom winger Chris Brunt has warned his team-mates they need to get tough if they are to stave off relegation.
The Baggies are now four points adrift of safety after Tuesday night's 3-1 defeat at home to Arsenal.
Tony Mowbray's men were made to pay for their defensive failings yet again as Nicklas Bendtner grabbed a brace and Kolo Toure helped himself to a simple header from close range.
Brunt, who briefly fired the Baggies back into the match at 1-1 with a low free-kick which crept through the Arsenal wall, believes that a lack of aggression throughout the team is proving costly.
"It all comes down to defending the ball when it comes into your box and we didn't do that," Brunt told the Express and Star.
"We have to stick together as a group of lads and be more aggressive as a team.
"It's well documented that we're not the most aggressive of sides but when the ball comes into the box we have to put our head on it and not doing that is what's costing us.
"It's disappointing because Arsenal haven't been in the greatest form and they have found it hard to score goals but we gifted them a couple.
"It's all well and good working on it in training and everybody knowing what to do before the game but if we don't put our head on the ball when it comes into the box teams are going to punish us and we have seen that in the last couple of games."
Brunt accepts the Baggies were far from at their best against Arsene Wenger's UEFA Champions League hopefuls and admits they only have themselves to blame for their latest defeat.
He added: "We weren't the better side but we were working hard and putting them under pressure and we got a couple of set-pieces.
"We grafted hard, although the quality wasn't great. We worked hard to get ourselves back into the game and we shot ourselves in the foot again.
"If we defend like that we deserve to lose. That's the way we defended on the evening and Arsenal won quite comfortably in the end."