Benaiah Ioelu could take Connor Watson's place in the Roosters' grand final side if Watson is ruled out.
"It's hard to put it into words, you always play the image in your mind as a little kid," Ioelu told AAP. "Being here this week and this moment, you're just super grateful for the opportunity that you've been given."
Watson's possible absence comes as Newcastle are without Phoenix Crossland for the decider against the Roosters.
Crossland was sent off for a hip-drop tackle in Newcastle's preliminary-final win over Penrith, after breaking Nathan Cleary's leg in an accidental tackle.
He received a four-game ban, and the Knights played the entire second half with 12 men.
Watson suffered a heavy blow in the Roosters' win over the Dolphins, receiving a Category 2 head injury assessment that was upgraded to Category 1 moments later.
Category 1 cases require an 11-day stand-down from training and competition.
Roosters coach Trent Robinson said Watson would see an independent doctor on Thursday, with the assessment then going to the NRL.
"Today is the day for him, he will get an independent doctor," Robinson said.
If cleared, the Roosters intend to present their case to the NRL; Manly's Tolu Koula was allowed to play after independent clearance following a Category 2 assessment in State of Origin 1.
A leading NRL reporter called the Roosters' effort a "bad look" and said expert authorities question whether 11 days is enough after a Category 1 injury involving loss of consciousness.