Pals Padraig Harrington and Paul McGinley will swap socialising for hard graft when they tee it up at Pebble Beach this week.

The pair reckon they have serious work to do on their games as they rub shoulders with celebrities like Caddyshack star Bill Murray or American football hero Peyton Manning in the $6.1 m AT&T Pebble Beach National Pro-Am.

Harrington struggled to knock the rust off his game in the Buick Invitational at Torrey Pines, eventually snatching a share of 24th thanks to a closing 68.

And while he admits that his rivals fear him coming down the stretch after last year’s Major double, the reigning PGA Tour Player of the Year knows he can’t afford to sit on his laurels.

The world No 3 said: “I wouldn't say there are too many pluses from the end of last year. I've still got to do a bit more work.

“I always work on my weak spots, always, always. I go all out to try and improve every year, try to get the whole package together. I am obsessive about it, yes.”

Harrington resists the temptation to slap himself on the back for his amazing Major feats over the past two years, even when his friends try to get him going.

He explained: “They sometimes ask me: 'Do I realise what I have done?' To be honest, you don't when you are involved in it.

“You just keep playing. Sometimes my friends will stop and try to get me to think about it but I kind of refuse and just keep going.”

McGinley didn’t play in any of last year’s Majors and hasn’t realistically come close to ending a victory drought that dates back to the 2005 Volvo Masters at Valderrama.

Ranked 22nd in the world at the start of 2006, he is now 121st after his worst start to a season for 17 years.

Making up the numbers in Abu Dhabi, where he was 67th, the three-time Ryder Cup winner missed the cut in Qatar and Dubai and badly needs a boost to his confidence.

In fact, he’s so desperate to find his game that he had the snow cleared on a patch of the practice ground at Sunningdale last week so he could hit balls.

Writing on his website for the first time in two months, he said: “First of all Happy New Year to everyone. Sorry it's a bit late but I've been busy practising.”

Describing his early season form as “very disappointing, he added: “My work rate and practice will continue to be accelerated in search of my form which I really feel is not a million miles away.”

Now a veteran at 42, McGinley struggled to 50th place at Pebble Beach last year while Harrington came home tied for 12th despite a heavy cold.

And the triple Major champion knows his rivals will be looking over their shoulders for him if he is in contention coming down the stretch on Sunday.

Harrington said: “I would hope they  would worry about me a lot more now. I think they would certainly worry me about me more if I was coming down the stretch.

“They know that if I am there on the back nine, there is going to be a real battle.”