Padraig Harrington misses a putt on the 18th on day two of the US Open at Congressional last month. Picture: Fran Caffrey/www.golffile.iePadraig Harrington must shake off his Harry Splutter tag and become Harry Putter again.

The Dubliner hasn’t made a serious challenge for a major since he lifted the US PGA for his third major win nearly three years ago.

But he believes he only needs “a spark” to ignite the competitive fires again and reckons his magical putter could hold the key to major No 4.

Rated a 40-1 chance for his third Claret Jug success this week, Harrington said: “I haven’t played my best golf so far this year so I’m still looking for that little bit of a spark.

“Maybe the week of an Open Championship is the place to find it. I wouldn’t be confident but I am optimistic.”

Harrington has bedded in his latest swing changes only to discover that his normally deadly putting form has faded in recent months.

It cost him a chance to win the Barclays Scottish Open last weekend but sees no reason why it can’t resurface on the roller-coaster greens of Royal St George’s.

Believing he’s close to firing on all cylinders again, Harrington said: “I’m probably hitting the golf ball a bit better than I have in the past. I swing it better and hit it better and the short game is strong enough.

“I just haven’t been putting it as well. That would be the normal strength of my game and I have to be patient with it and let it come back.”

Having two Claret Jugs on the kitchen table at home gives Harrington confidence that he can win a third.

Another Open win would put him level with legends such as Bobby Jones, Henry Cotton, Gary Player, Jack Nicklaus, Seve Ballesteros, Nick Faldo and Tiger Woods.

And while he turns 40 next month he believes he’s still got plenty of fuel in the tank as he searches for major No 4.

Dismissing claims that he’s happy with his major haul, Harrington said: “Obviously winning Majors would have been beyond my expectations at the start of my career. I would have been happy to win three tournaments. That would be a sucessful career.

“But now I’ve done it, I have high expectations going forward.  But it brings a lot of pressures with it and you have to deal with that.

“I feel in a good position going forward and feel very optimistic about my game.

“We’ll wait and see how it goes this week but it doesn’t have to happen this week – it can happy at any of the Majors.

“I’ll get another 26 Majors before I’m finished so I’m okay in that sense. I’ve got the game to do it and I feel in good stead.

“I won’t say I’m playing the best golf of my life but I’m quite happy where I’m at and, certainly, it could be around the corner.”