Sunderland winger McClean was furious that Trapattoni did not bring him off the bench on Friday night as the Republic struggled to a 2-1 win over eastern European minnows Kazakhstan.
In an apparent broadside at Trapattoni's refusal to call on his services, the Sunderland winger tweeted: "Delighted as a fan we got the the win.. Personal level fuming #f****njoke #embarrassing."
Trapattoni spoke to McClean about the tweet, which the midfielder quickly deleted, and the player issued a full apology on the micro-blogging website this afternoon.
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."
Trapattoni then also spoke to McClean in front of the whole squad before the player apologised to his team-mates in the room.
Trapattoni had considered dropping McClean from his squad for the outburst, but the former Derry City man's apology means he has been retained for the Emerald Isle's international friendly against Oman at Craven Cottage on Tuesday.
The tweet once again raises questions about Trapattoni's relationship with some of his players. Having seen Damien Duff and Shay Given retire from international football this summer, the Italian was then disappointed by the actions of Darron Gibson, who refused a call up for these two games.
And last month Wolves utility man Kevin Foley turned down the chance to play for his country in their friendly against Serbia and vowed never to play for Trapattoni again because he felt the Italian "betrayed" him by excluding him from his European Championship squad.
Kevin Doyle on Saturday tried to play down talk of unrest and insisted the whole Republic squad are behind Trapattoni, whose position would have been under intense pressure had Doyle and Robbie Keane not scored two late goals to snatch all three points last night in the former Soviet republic.
"Everyone is together," Doyle said. "Everyone respects the manager 100% and there is no other scenario.
"Honestly, it's the same as any squad I have been involved in with Ireland. Everyone is entitled to their opinion and feeling but as far as I can see everyone is right behind the manager and hopefully that win will ease the pressure on us."
Having travelled halfway across the planet to make yesterday's qualifier in Astana, Robbie Keane and Darren O'Dea have been allowed to miss the friendly against Oman.
Sunderland's John O'Shea, and Stoke duo Jon Walters and Glenn Whelan have also returned to their clubs.
Reading defender Alex Pearce has been called in to the squad along with 20-year-old Manchester United winger Robbie Brady.
Trapattoni rang Under-21 manager Noel King after the Ireland-Kazakhstan game and requested Brady be excused Monday's UEFA Under-21 Championship game against Italy in order to link-up with the full squad.
King said: "Robbie has deserved his call-up. He's been sensational for us - as the people of Sligo will testify after his previous performances in the campaign.
"He sets the place alive and some of his play has been outrageous."
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
The push for more color on their cleats, adidas has added the infrared colorway to the adiZero f50 Line.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.
The new PUMA evoSPEED 1.2 FG. A great new soccer cleat with classic look and first time for PUMA to be on the cleat.
The adidas Nitrocharge is the most talked about new cleat in years. It was released on May 15 and will take your pitch by storm.