The England Under-21 international was red-carded after Tuesday night's 1-0 European Championship play-off victory against Serbia in Krusevac amid allegations that he and other black players had been racially abused.
O’Neill 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."