McClean was furious at not being called off the bench during the clash in Kazakhstan, which the Republic won 2-1 thanks to late goals from Robbie Keane and Kevin Doyle.
He wrote on Twitter after the game: "Delighted as a fan we got the win.. Personal level #fuming #f****njoke #embarrassing."
McClean deleted the tweet within 15 minutes, but it had been widely noticed and he returned to Twitter on Saturday morning to issue an apology.
He wrote: "i apologise for my tweet last night, it was stupid, disrespectful and i let my frustration get the better of me which still aint an excuse."