NEWCASTLE Jets co-captain Brandon O'Neill will miss the F3 derby against the Central Coast in Gosford on Wednesday and the midfield linchpin could be sidelined for up to a month.
O'Neill damaged the medial cruciate ligament in his knee during the Jets' 1-0 loss to Brisbane Roar at McDonald Jones Stadium on Friday night.
The industrious playmaker completed the game but pulled up sore.
Both coaches were highly critical of the patch-work playing surface which was relaid after a round of the Australian Supercross series on November 26.
O'Neill has started every game this season at the base of midfield and was outstanding in the 2-1 win over the Mariners on December 11.
Either Callum Timmins or Mo Al-Taay are expected to join Angus Thurgate and Beka Dartsmelia in the centre of the park.
The Jets produced their best half of football in the opening 45 minutes in the first encounter against the Mariners.
"The fact we have beaten them quite recently helps our confidence going into the game," in-form defender Mark Natta said.
"I thought our first half was definitely one of our better halves.
"We kept the ball well and we looked dangerous. We weren't just keeping the ball, we were going forward and being positive. That is what the boss wants. Keeping possession is the main focus but having possession with a purpose."
The Mariners were adamant that they deserved at least a point from the match after the VAR rubbed out what would have been an equaliser for a handball in the lead up.
The win was the Jets' first over their neighbours since June 1, 2021.
They were under the pump for much of the second half, especially after the introduction of Garang Kuol.
The Socceroos wonder boy was promoted to the Mariners' starting side and responded with an assist in the 2-1 triumph over Sydney FC on Saturday.
His inch-perfect cross in the 35th minute found the head of Marco Tulio, who nodded home. It was Kuol's third assist of the season to go with two goals.
Incredibly, it was the 18-year-old's first start in the A-League. And with just three games remaining before he leaves for England and a deal with Newcastle United, coach Nick Montgomery plans to get full value.
"Kuol is obviously an explosive player," Natta said. "We know that and will be prepared for that. He is aggressive and runs at players. Our defensive line will be fine. That is our job. There is nothing to be scared of. I love versing the best players. It is what you want to do. It helps me grow and get better. So far this season I have come against some top strikers and I think I have improved already.
"The Mariners play a very attacking brand of football. If we can stay compact, defend well and win the ball, that gives us a chance to hit them on the counter.
"When we have the ball and sustain possession is when we look dangerous."
As well as Kuol starting, the Mariners welcomed back centreback Brian Kaltak from suspension.
The Jets dominated possession against the Roar but struggled to break down a compact defence.
Reno Piscopo missed the Roar match but is back in full training and in contention. Jaushua Sotirio, who nearly snatched a late equaliser, is also pushing hard for the a start.
At the other end, the Jets gave up a sloppy goal from the second phase of a freekick.
"On the weekend we were pretty compact," Natta said.
"There were maybe a couple of moments in the box when we switched off.
"Those are the things we have to fix up. The little moments, the one per centers in the box."
The Jets sit in 10th spot on nine points, a point behind the fifth-placed Mariners, who are among five teams on 10 points.
Just three points separates third placed Adelaide (12 points) from the Jets. Wednesday's derby is a catch-up game after their round one match was washed out.
