Ponga has been the recipient of a number of head knocks this season, the most recent coming during Round 19 against the Sydney Roosters where he played just eight minutes before being taken from the field and not allowed to return.
It was reported shortly afterwards that his season would be shut down due to the knock, and the fullback has now confirmed that to be the case.
Spekaing to Triple M Radio in Newcastle, Ponga said he could have realistically returned for the final round of the season, but has decided against it on advice with medical staff after weeks of no contact as he works through NRL concussion return to play protocols.
"I'd be sweet for the last round but doing no contact for the year, it probably would be a wise thing not to play the last round," Ponga said.
"My season's done.
"It's a bit weird. I feel OK now. At the start I felt a bit weird, headaches and whatnot, but I feel alright now.
"It's just hard. I feel OK. I feel fit. I want to play but I guess I'm just going through the protocols at the moment."
The news is the latest blow for the Knights, who have managed to avoid the wooden spoon barring a catastrophe, but will likely wind up in the bottom four at the end of the season following their latest loss to the Brisbane Broncos on Saturday evening.
Ponga said the symptoms for concussion are no longer prevalent.
"It is tough. I feel sweet. There's nothing wrong with me," he said.
"I can't feel anything but I just have to trust the process that's ahead of me."