Padraig Harrington shrugged of his FedEx Cup KO by heading home for a Major celebration party.

Ireland's triple Major champion limped home a massive 18 shots behind BMW Championship winner Camilo Villegas when he finished 55th in St Louis on Sunday night and failed to make the season-ending Tour Championship.

But despite missing out on the $10 million FedEx Cup jackpot destined for Vijay Singh's bank account, Harrington will finally get to celebrate his US PGA victory on Irish soil when he hits the tables at Dermot Desmond's Sporting Emporium gaming club for a private party this week.

Exhausted after a six-week run in the US, Harrington said: "I obviously hoped I could get into the FedExCup and perform, but that's not the case. In hindsight it was a step too far. But there you go.

"Actually the game is fine, so my intention would actually be to rest this week. There's nothing in my game that I'm unhappy with.

"I just need to make the right decisions a bit more often and the fact that I didn't is a sign of a little bit of tiredness, really."

Having started the play-offs in fourth place thanks to his PGA win at Oakland Hills, the world No 4 slithered all the way down to 44th heading to St Louis.

He needed a top-seven finish to qualify for the Tour Championship finale through the top 30 in the FedEx Cup rankings.

But he simply didn't have the mental strength to pull it off and ended up 50th in the table.

He added: "Actually it was tough going. I didn't really hole putts in the last three rounds. But I suppose, that was as expected."

Harrington has just a week to recharge his batteries in time for next week's Ryder Cup showdown with the US at Valhalla.

Asked if that was enough time, he said: "I hope. It's not as if I have a choice."

Colombian poster boy Villegas grab his maiden PGA Tour win at Bellrive to jump from 25th to second in the FedEx Cup race.

But Singh's 44th place finish means the Fijian will pocket the $10 million FedEx Cup bonus, even if he finishes dead last in Atlanta in a fortnight's time.

Several PGA Tour players have expressed amazement that double major winner Harrington will not be playing the Tour Championship.

Yet Harrington has no complaints about his exit, though he believes the system needs to be tweaked slightly to maintain excitement levels right to the end.

Harrington said: "We need to have players get knocked out. That's what happens in a playoff.

"I would reduce the points in the first two weeks for just making the cut, increase the points higher up, probably double the points in this week to make it as volatile as it was in the last couple of weeks and double the points again at the TOUR Championship."

The bad news for Harrington is that he cannot now win PGA Tour's Byron Nelson Award for the lowest scoring average this season.

Phil Mickelson (69.52) and Sergio Garcia (69.53) will battle for that honour in the Tour Championship after Harrington (69.67) slipped from first to fifth in that statistical category.