Dylan Lucas' late return from injury strengthened Newcastle's hopes after its 12-10 elimination of the Warriors in Auckland on Sunday.
The Knights now face Penrith at Accor Stadium, with victory sending them into the grand final and completing a remarkable turnaround.
Newcastle finished with the NRL wooden spoon last season, while the Roosters were the last team to go from last in 2009 to finalists the following year.
Captain Kalyn Ponga will play after passing his head injury assessment, despite watching the closing stages against the Warriors from the dressing room.
He rejected any immediate celebration of Newcastle's progress under first-year coach Justin Holbrook.
"You want to get your mind to the next game, and that's been the strength this year."
Ponga said he would appreciate the season later, but insisted the team's work was unfinished.
"All I do know is I'm really proud of this group for the efforts that they've put in throughout the whole year. I don't want to reflect too much just yet."
Lucas' 20-minute appearance offers further encouragement as Newcastle continues without first-choice forwards Jacob Saifiti and Trey Mooney.
The Knights have also maintained their attacking threat despite losing playmaker Dylan Brown to injury.
"So many times we've had injuries, had to overcome adversity and challenges, and as a playing group, we've handled that pretty well. No doubt it'll be the same next week."