Newcastle have lost star centre Bradman Best to a recurrence of his hamstring injury for their elimination final against North Queensland.
AAP has been told Best would not play in the do-or-die clash, only two weeks after returning from another hamstring issue.
The injury is not believed to be serious, and there is a hope Best will play again this season if the Knights progress past this week.
But after experiencing hamstring tightness following Newcastle's last-round win over the Dolphins, the Knights opted against the centre making the long trip to Townsville.
Best's absence will come as a blow to the Knights, who had benefited from having he and Kalyn Ponga firing on the right edge in recent weeks.
The Knights' top-eight credentials appeared in disarray when Ponga was diagnosed with a Lisfranc injury in his right foot as the side sat 15th on the ladder through seven rounds.
But after Newcastle held themselves together in his absence, Ponga hit top gear on return for the final two months of the regular season.
Ahead of facing the Cowboys, Ponga put his form down to a mindset shift during an 11-week lay-off.
"Coming back from my injury, I sort of felt like I had a point to prove," Ponga said.
"Just proving that the best version of myself is the best. When you're injured, you're not really the best version of yourself. You're coming back from rehab, you're doing all that.
"Once I'm on the field, I want to be the best version of myself so just making sure I do everything day to day to do that."
Ponga made a similarly emphatic return from injury towards the end of last season, shaking off a serious concussion to inspire a 10-game winning streak that stretched to the second week of finals.
"I've been injured the last half of each season so then I'm kind of timely at the back end," Ponga said.
The Knights spent only three weeks in the top eight this season, the fewest for any finals team since Canberra in 2010, but Ponga always felt the side was play-off material.
"We've seemed to put it together at the right time over the last three, four, five weeks (but) it's not a coincidence," he said.
"I think we've just stuck at what we thought was happening, what we were doing right and it's sort of just coming along."
Ponga returns to his old stomping ground this weekend, having made his NRL debut on the wing in North Queensland's 2016 semi-final win over Brisbane.
The 26-20 victory ranks among the former Cowboy's best memories on a rugby league field.
"It all happened very quick - young 18-year-old with no idea what was really going on, how big the occasion and everything was," Ponga said.
"Being naive and young was probably in a way a favour, not really understanding the work that had been done to get into that position.
"It was probably one of my favourite experiences, really."
