Initially, Ponga had been playing the six role for O'Brien prior to sustaining a head knock in the Knights' gritty Round 2 win over the Wests Tigers, however, the Queensland rep will now return to his natural habitat at the back.
Miller has been asked to ride the pine by O'Brien, relegated from his starting role to riding the bench for Sunday afternoon's home clash against Manly.
Yet, while Ponga will be steering the Knights from the back at Miller's expense, O'Brien stated that the positional shift was not made solely to suit his star, but in an effort to elevate Tyson Gamble's impact on games.
“The reason isn't based around Kalyn alone,” O'Brien told News Corp ahead of kick-off.
“I felt I needed to get Tyson back out there and playing a lot more. We've played a lot more good footy when he has come onto the field.
“He was only getting 20 minutes off the bench but against the Titans, there was a real difference when he came on. He and Jackson Hastings are really connected in the halves."
Since joining the Hunter side at the start of the 2023 season, Miller has seen his form dip - a fact that hasn't escaped O'Brien's notice.
While early plans initially saw Miller out of O'Brien's side, the former Olympian's flexibility saw him earn a reprieve and a bench slot to face the Sea Eagles.
“He started the season on fire, but over the last few weeks, he is down on confidence and came up with a couple of errors. He is trying really hard but I want to alleviate some pressure on him,” O'Brien said of the Coffs Harbour native.
“The plan was for him to go to NSW Cup and work on a few things but having a look at him at training, we used him as a 14 and he looked really good.”
The Knights and Sea Eagles will face off at McDonald Jones Stadium at 4:05pm (AEST) on Sunday afternoon, with Ponga selected to wear the one, Gamble the six and Miller the 14 in O'Brien's 22-man squad.
Newcastle's squad will be cut to 19 at 4:05pm on Saturday afternoon.