While the Black Cats have slipped to within a point of the bottom three after a run of just one win from ten Premier League matches, Rose has been one of the brighter elements of the team's displays.
After a slow start to life at the Stadium of Light following his season-long loan switch from Tottenham, the 22-year-old has grown in confidence and looks far more comfortable in a red and white shirt.
Sunderland manager O'Neill initially showed a reluctance to field the Spurs young gun, but now he has become a concrete starter after a string of promising displays from the back.
The club's fans, who are frustrated with the poor form overall, have immediately warmed to the improved performances from the England Under-21s international.
And O'Neill said: "I know what he is capable of doing and that is why I brought him to this football club. You have to nurture him. He is getting fitter and that was the most important issue.
"The reason he is getting better is because he is getting fitter and I'm talking match fitness. He never played enough matches at Spurs. He came in at the back end of last season. As he is getting fitter he is getting more confident and the crowd are getting right behind him. It makes it easier for him."
Ironically Rose's best displays in a Sunderland shirt have arrived on the back of one the worst nights of his burgeoning career.
He was at the centre of a forgettable night in Serbia in October when he was racially abused during England Under-21s European Championship qualifier success in Serbia - allegations the Serbia FA denied.
But he has successfully put that to the back of his mind. O'Neill said: "For the Under-21s he can go marauding but it is a different intensity in the Premier League. He has got used to that now.
"You look at his first couple of games for us, he got it and gave it. He played within a zone. But he is now confident and I knew he was capable of doing a lot better than that.
"He was sad about what happened in Serbia. It was on his mind, but he tried to separate that situation and he has done."
Now O'Neill needs to ensure more of his players follow Rose's lead and try to revive low confidence levels after a depressing run of form.
Sunderland face Chelsea this weekend knowing a seventh defeat from 11 games could see them drop in to the bottom three.
The Blues are hoping to have John Terry, Frank Lampard and Daniel Sturridge available for the trip to the North-East after injury, which is hardly the ideal news for a Sunderland team struggling to climb the table.
O'Neill's biggest concern will be who to play up front if, as expected, £12m striker Steven Fletcher is ruled out with an ankle injury.
Sunderland have still not revealed the extent of the damage sustained during Sunday's 2-1 defeat at Norwich City, but even in the best case scenario he is unlikely to face Chelsea.
That could open the door for teenager Connor Wickham. The 19-year-old has been on the periphery since his £8.1m switch from Ipswich 15 months ago and has been waiting for a chance under O'Neill.
But with Fletcher still being assessed and Louis Saha recovering from a knock which ruled him out of the trip to Carrow Road, Wickham's big start could arrive against the European champions on Saturday.
* Sunderland supporters are being reminded there are still tickets available for this Saturday's visit of Chelsea and the rearranged Reading fixture on Tuesday, December 11.
Tickets for the Chelsea date are priced £27 for adults and £12 for under 16s. The Reading prices are from £25 for adults and £10 for under 16s.
Supporters are advised that tickets purchased for the original Reading fixture in August are still valid for Tuesday night's game.