James McClean vented his frustration after Republic of Ireland manager Giovanni Trapattoni left him on the bench to watch his team-mates struggle to a 2-1 win over Kazakhstan on Friday evening.

Trapattoni, who has come under pressure this summer after the country's dismal showing at Euro 2012, saw his Republic of Ireland side put on arguably the worst performance of his four-and-a-half year tenure tonight.

Kazakhstan, who are ranked 142nd in the world, outplayed the Republic in Astana and took the lead nine minutes before half-time through Kairat Nurdauletov.

The former Soviet Republic then could have scored at least two more goals before they collapsed in a frenetic final two minutes which saw the visitors snatch victory thanks to goals from Robbie Keane and Kevin Doyle.

Trapattoni brought Doyle and Shane Long off the bench but did not call upon McClean, who has been outstanding for Sunderland this term - a move that has clearly enraged the 23-year-old.

Tweeting from his official account @JMcC--23, the winger said: "Delighted as a fan we got the the win.. Personal level #fuming #f****njoke #embarrassing."

The tweet was later deleted.

Trapattoni is aware of McClean's rant and could fine the former Derry City man for his actions, or even kick the player out of the Republic's squad for their friendly against Oman at Craven Cottage on Tuesday - a game in which he probably would have started.

McClean is not the first person to become enraged at sitting on the bench for the Republic in recent times.

Darron Gibson refused a call-up to the squad for these two games as is still smarting from Trapattoni's refusal to bring him on as a substitute during Euro 2012.

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.

Trapattoni has been at pains to stress all week that the squad is united and determined to embark upon a new successful era following the retirements of Damien Duff and Shay Given.

Despite the rhetoric, however, the Italian's team were woefully below par, with Kazakhstan the better side for the majority of the match.

Ireland often resorted to lumping the ball up to Jon Walters in a subdued first half - a tactic that never really worked - and the team lacked penetration off the flanks.

Had it not been for two excellent saves from Keiren Westwood, and the woodwork, Kazakhstan could have run riot here in Astana.

Afterwards, a downbeat Trapattoni admitted his side were fortunate to start their Group C campaign with a victory.

He said: "I think it's honest to say that we have been a little bit lucky in this game.

"I think we had a psychological block after we conceded because usually we have a good reaction when that happens but we didn't today."

His opposite number Miroslav Beranek agreed.

"Football showed its brutal face to us tonight," the Kazakhstan coach said.

"We played very well so it's really hard to speak about these goals we conceded."

It took until the 89th minute for the Republic to make an impact on the game.

Mikhail Rozkhov tangled with Keane deep near the Kazakhstan goalline and the Los Angeles Galaxy striker duly converted from the spot.

Kazakhstan's players were unhappy with the decision, Beranek revealed.

"I personally didn't see the penalty but the players said it was just a duel for the ball," he said.

The Republic carried their momentum on from the restart and with 30 seconds left Kevin Doyle smashed home from close range after the ball pinged around the away goal-mouth.

"It was a smash and grab job," the Wolves striker said afterwards.

"We got out of jail. It's good to start the campaign with a win but with minutes to go, it looked like being a disaster.

"I felt sorry for Kazakhstan but there's plenty of times when it's been the other way round so I can't feel too sorry for them."