Newcastle Jets coach Branko Culina wants his team to toughen up for this weekend's Round 26 derby with the Central Coast Mariners.

The Jets gave up a one-goal lead last night as they went down 2-1 to North Queensland Fury in their rescheduled Round 25 fixture, causing them to drop to sixth on the table which means they are on the verge of falling out of the finals race if results do not go their way.

But the Jets can book themselves a spot in the play-offs if they defeat the Mariners this week and Culina wants a drastic improvement.

"If we start looking for excuses all the time that's all we'll ever end up doing," Culina said.

"We'll be looking for excuses to justify this that and the other, and we're better than that. We have to learn from the mistakes we make.

"[The rescheduling] was always going to be a problem for us. That's why the three points [missed on Tuesday night] were vital.

"The Central Coast game, especially with the rescheduling [and] after the loss, is maybe not such a bad thing."

Culina urged his players to become harder and more aggressive and to stop giving away easy goals so they can give themselves the best chance of possible as the 2009/10 season comes to a close.

"I think you have to be hard to beat and at the moment we're not," he added.

"We have to learn to be hard to beat and not concede stupid soft goals as we do week in week out.

"Until you learn to do that you're always going to be a team that is going to be up and down and if you want to be a top team you cannot concede such soft goals."