The England Under-21 international was sent off during Tuesday night's 1-0 European Championship play-off victory in Krusevac amid allegations that he and other black players had been racially abused.
Rose, currently on loan to the Black Cats from Tottenham, was back on Wearside on Thursday, but O'Neill revealed he will wait before deciding whether or not he is mentally prepared to play in Sunday's Barclays Premier League clash with Newcastle at the Stadium of Light.
He said: "I will give him the opportunity just to let things lie for a day or two and I will speak to him closer to the time and see what frame of mind he is in.
"You are hoping that young players who might not have experienced things like that there before can respond positively.
"I am sure he will do and hopefully at some stage or another, he will take it in his stride.
"But I would just really point out that everybody here at the football club, and I am quite sure at his own football club, is very much on his side."
Rose and his team-mates were clearly furious and the game descended into an ugly brawl on the final whistle.
Both national associations have since been charged by UEFA in connection with the incident with the Serbian FA, to the astonishment of their English counterparts, having branded Rose's behaviour "inappropriate, unsportsmanlike and vulgar".
O'Neill was reluctant to comment until all the facts are available, but said: "He is naturally disappointed with the state of affairs, and somewhat angry as well, but I am sure there will be a lot more said about it in the next few days.
"Maybe until we get the full picture, from my viewpoint maybe the less said, other than the fact that I think it's been very, very disappointing, particularly considering the efforts that have gone in over the last couple of seasons here to eradicate racism from our game.
"It is a difficult situation for him and I have obviously the utmost sympathy for and empathy with him.
"It's something he shouldn't have to endure, and that goes for all concerned.
"I notice he had some words with the assistant manager (Steve Wigley), who said to him at the time, 'Listen, try to get through and then we will fight the case afterwards', and I think that's probably what is going to happen."
If 22-year-old Rose plays on Sunday, he will step into a cauldron of a different kind as the north-east neighbours resume hostilities.
Newcastle won 1-0 on Wearside last season and Sunderland were denied revenge on Tyneside in March when Shola Ameobi's last gasp equaliser saved face for the Magpies.
O'Neill, a veteran of the Old Firm derby in Glasgow from his days as Celtic manager, admitted the intensity is similar.
He said: "I have been involved in quite a number of derby games, hardly that many bigger than the Glasgow ones between Celtic and Rangers, but for intensity, this is up there with any of them.
"I like the intensity of the games, as long as it doesn't go overboard, that's an important aspect to derby matches.
"Steve Walford, my coach, has with me experienced a lot of derby games and in particular, Celtic v Rangers games, and he felt the game at St James' Park matched that for intensity, and some of the games we had with Celtic and Rangers, so that speaks volumes for it."
That intensity did boil over on Tyneside in March when Newcastle boss Alan Pardew celebrated the award of a penalty in front of O'Neill and his staff, sparking a confrontation between the two benches.
O'Neill said: "A number of things can happen in the spur of the moment which you can be very embarrassed with and you can be very annoyed with yourself afterwards.
"I just hope that both of us might be able to learn the lesson from the previous encounter."