Royals defender Harte labelled Trapattoni a clown recently after being overlooked for the friendly against Poland.
Now Harte, 35, has defended the outburst on Twitter - and gone further.
Harte said: "I tweeted what I did out of frustration. I'm not for one minute saying that I should be in the team.
"I just think that with my experience, what I've done in my career, and where I'm playing at the moment - in the Premier League, against the best footballers in the world - then I should be given a chance. That's all I've wanted - a chance.
"I'm a passionate Irishman and I just think it's killing Irish football at the moment.
"He's stuck in his ways, and he seems to have his favourite XI and if they're fit, they will play, no matter how they are doing at their clubs.
"The other lads that are doing well for their clubs? What do they have to do to get the opportunity?"