After their best ever start to a Hyundai A-League campaign the Jets have fallen into a form slump and have earned just one point out of a possible 15 over the last month and a half.

To arrest the slide the former England international said that the Newcastle side must fight doggedly for every point on offer.

"(Against Sydney) it is a win or a draw, just not losing. We have to get back to that way of being resilient, being hard to break down, being tough and being aggressive," Heskey said at training on Tuesday.

"We have to dig deep and battle.

"Confidence is down (although) we are playing some good football but we are not getting the results we think we deserve.

"But we have to pick ourselves up, keep on training and pick it up in the game, and we have to do that ourselves."

After starting his A-League career in red hot form with five goals in the opening six matches Heskey hasn't found the back of the net since the November 10 win over the Wanderers.

The veteran striker acknowledges that opposition teams have worked out the Jets' game plan and cut down supply to him but he insists that his side must come up with better ways to attack and defend.

"(We need) different ways - we have to do things better. We are conceding too many goals and not scoring enough so we have things to work on," he said.

"Frustration is just not with me, it is going through the whole team, but you know that is for us to have formulas to break them down.

"If teams are putting two, three men on me then there is space elsewhere to exploit, so we have to work on that."

Heskey said that their come-from-behind win over Sydney FC earlier this season was probably their best performance of the season and added they would be looking to reignite their season with a similar performance this weekend at Hunter Stadium.

"We do try to emulate that but we have had different formations and different formulas," Heskey said.

"We are working on things and that is what we are trying to do put in more performances like that."

With speculation hanging over the future of Sydney marquee Alessandro Del Piero this week, Heskey said it was important for the Italian superstar to keep leading from front for the Sky Blues.

"He is a great player," Heskey said.

"He has achieved a lot over the years and is a great ambassador for the game so it is nice to have someone like that in football in Australia and he is working wonders."