McClean, who held talks with O'Neill on Friday faces hefty fines from his club if he uses language to incite further problems.
O'Neill said: "Is he maturing? No. He has gone back on Twitter, even against advice of the club. I have to say maybe he will look out for himself then.
"I am learning these things all the time, such as from my daughters. I have no major problem with people going on these things but what they don't seem to realise is that when they go out there it goes into the public domain.
"As long as he doesn't start to talk about the football club and use derogatory comments, then fine, and as long as he doesn't swear.
"These are the things I would take exception to. You might say it is the kettle calling the pot black, I know. I am not so sure what we can do. I will have to really have a look at it and see. Has he learned? We will see. I am allowing it to settle down."
He added: "Do I expect to get a tweet calling me a clown? I wouldn't be surprised. I dare him to do it."