WHEN European team-mates Sergio Garcia and Padraig Harrington shook hands on their differences at the 2008 Ryder Cup in Valhalla, the Spaniard confessed to the Dubliner how much he had wanted to "break that putter over your head".
As he crushed Garcia a month earlier in the final round of the US PGA Championship to win his third Major title in 13 months, Harrington putted imperiously, especially down the stretch at Oakland Hills.
If putting separated them in Detroit five years ago, it was the essential difference between Harrington and Garcia once again at Muirfield on Saturday.
Only this time, the 41-year-old Irishman grappled with demons of self-doubt on the greens, as he failed to register a birdie in his third-round 77, nine strokes worse than an impressive 68 by Garcia.
Harrington's faint hopes of carving out a top-10 finish at the 2013 Open expired.
After closing with a one-under-par 70 yesterday, Harrington finished in a share of 54th on 11-over, lamenting a paltry tally of six birdies in 72 holes at Muirfield, precisely the same as in last month's US Open at Merion.
Throw in a missed cut at April's Masters and it has been a fruitless and frustrating season for Harrington at the Majors.
Yet unlike Garcia, who took a complete three-month break from golf in 2010 saying, "I need to miss the game a little bit", Harrington is a relentless fighter.
No matter how torrid things get for him on the course, he will battle on. With three Major trophies on his sideboard in Rathmichael, he could rest on his laurels. "I could, but that won't happen," he insisted.
"A lot of pressure comes with winning a Major, including the frustrations of not getting that high again. The reward only comes when you stop playing, and I have no intention of stopping!"
Much was made in print of a tetchy remark by Garcia to a rules official on the way to the 15th tee on Saturday when he complained that telling Harrington they were no longer on the clock led to "the automatic handbrake" being engaged again.
Under the terms of their 'Valhalla Accord', neither will say a word against the other.
Yet Garcia's little exchange with the walking official and the couple of occasions he'd rushed to the next tee and was ready to go before Harrington arrived illustrated the Spaniard's frustration at the amount of time and attention his playing companion devoted to even the shortest putt.
Watching Harrington putt can be excruciating these days, though he insists there is no inclination to break the belly putter he has used since May over his own head.
Quite the contrary, in fact, as Harrington said: "I'm delighted with my putting!"
Instead, he attributed his failure to make birdie on any of the par-three or par-four holes at Muirfield to a continuing "lack of trust" in his reading of greens.
Never mind the swing changes Harrington infamously made after his world-conquering feats in 2007 and 2008.
He has slumped out of golf's upper echelons because of the negative impact the 2010 ban on box-grooves had on his wedge play and, principally, a marked decline in his confidence on the putting green.
Albeit controversial, the belly putter appears to have put manners on Harrington's stroke.
This leaves his difficulty reading and believing the line of longer putts as the Dubliner's biggest bugbear.
Languishing well outside the world top 50, Harrington is ineligible for the cash and point-rich Bridgestone World Golf Championship at Firestone next week, so he plays the Reno-Tahoe Open, where the modified stableford points scoring system will be anathema to a golfer struggling to make birdies.
These are hard, frustrating times but the Irishman firmly believes redemption is just a birdie putt or two away.