The 24-year-old Republic of Ireland winger has endured an eventful 18 months since bursting on to the Barclays Premier League stage with Sunderland and quickly establishing himself as a full international.
However, having already found himself at the centre of controversy for opting to represent the Republic rather than his native Northern Ireland, the Derry-born midfielder has repeatedly landed himself in hot water as a result of messages posted on social networking site Twitter, and his refusal to wear a Remembrance Day poppy on his shirt.
Both Trapattoni and former Sunderland manager Martin O'Neill have had cause to reprimand him as a result, and the message appears to have finally hit home.
McClean said: "Both Martin O'Neill and the manager have had a word in the past. I feel a bit bad now because I haven't been the easiest.
"But I take that on board and I think I have matured a bit in the last few months, and I will continue to hopefully do that."