Jackson's left knee buckled awkwardly underneath him when he tried to block a cross in the 23rd minute, and he was helped from the field in obvious distress.

Because of the Australia Day long weekend, the 24-year-old will have to wait until Tuesday for scans to verify the extent of the damage.

He will be desperately hoping he has not torn his anterior cruciate ligament, which would likely mean reconstructive surgery and a six-month recovery period.

Newcastle's loss - their seventh in their past eight games - left them last by four points, but their nearest rivals, Central Coast, were unable to extend the gap after losing 1-0 at home to Brisbane on Saturday.

The Jets now face consecutive home games, against Western United on Saturday and the Mariners on Sunday week, that might well determine whether they collect the dreaded wooden spoon.

Newcastle's caretaker coach Craig Deans may have to remain at the helm for a fourth game after chief executive Lawrie McKinna said on Sunday there was "no update" about the club's quest to replace Ernie Merrick, who was sacked on January 6. Deans said he could not question the effort or attitude of Newcastle's players since he took charge but felt they would respond positively to the arrival of a new head coach.

"If you look at the team, they don't look like a team that's lacking direction," Deans said.

"But it might just be that little extra push that we don't have at the moment, knowing that the person that's in charge is going to be there for a longer period of time and they're able to make some big changes if they want to.

"At the moment we're in a bit of a holding pattern."