The 23-year-old Republic of Ireland international incurred the wrath of his team-mates last week when he hit out at manager Giovanni Trapattoni's decision to leave him sitting on the bench during his country's 2-1 World Cup qualifier victory in Kazakhstan on the social networking site.
Black Cats boss Martin O'Neill said: "He has a bit of a problem and we will have to rectify it. We can have a bit of a joke about it and laugh about it and think: 'Well, that's okay'."
McClean has since issued a humble apology to both the 73-year-old Italian and the rest of the Republic squad and closed down his Twitter account, and played the final 30 minutes of Tuesday night's 4-1 friendly victory over Oman at Craven Cottage.
However, O'Neill has revealed the matter will be discussed further on his return to Wearside and the player will be told in no uncertain terms what is required of him.
He said: "James has been acting rather strangely. It's good when the player not only wants to play, but he also wants to manage the team as well.
"James is rather young for that at the moment. I think Mr Trapattoni has got a couple of years on him and a couple of titles too in front of James, so I think he's entitled to pick the team.
"He has even admitted himself he has been rather foolish. He has taken himself off Twitter, apparently then he might have a situation with Facebook as well and about 14 other accounts that he has."
Referring to his club's policy on such matters, he added: "He does know the rules - they were read to him, they were given to him, he was there that day - and, not only that, some of his language was pretty poor and we will have to deal with that.
"Genuinely, we can have a laugh about it first of all, but now it's getting a bit ridiculous."
Source: PA
Source: PA