OAKMONT, Pennsylvania (Reuters) - Nine years after conquering Tiger Woods and the rest of golf's elite, Argentina's Angel Cabrera returns to Oakmont Country Club as a 300-1 long shot to emulate his 2007 U.S. Open victory.

As the focus this week has been on the likes of Jason Day, Jordan Spieth and Phil Mickelson, Cabrera slipped into town almost unnoticed, like a party guest invited to make up the numbers.

Not that anybody could be blamed for overlooking Cabrera, because his recent form has been absolutely dreadful.

He has only one top-40 finish all year – a tie for 24th at the Masters – while plummeting to 389th in the world rankings.

Cabrera has perhaps never received the widespread credit he deserves for winning two major championships and losing a playoff in another.

Apart from his U.S. Open victory, he clinched the 2009 Masters in a playoff with Kenny Perry and Chad Campbell, and lost the 2013 Masters in a playoff with Adam Scott.

Consistency has never been his strong suit, but it has been a wretched season for the 46-year-old, even by his own up-and-down standards.

The pertinent question is whether Cabrera is now over the hill, or just going through a lull?

"It's already been proved that for some reason I just play better at majors than regular tournaments," the Argentine told reporters, via an interpreter, on championship eve on Wednesday.

"There's something about the majors that gets a lot of focus from me, a lot of the best of me, and that's been basically the case for all of my golfing career.

"(At) the 2007 U.S. Open, I was hitting the ball so well off the tee, and I made some crucial putts that week. That was the mental part of the game that was better than any other week."

But though those memories are obviously cherished and the talk of raising his game for the majors has validity, the cycle of life is relentless, and Cabrera finds himself bereft of confidence right now as the clock ticks on.

"It's been a very tough season for me. I haven't been playing well," he said.

"I know that ... a U.S. Open is going to take the best of me, and I'm not in the best position to actually play right now, but I hope just not to suffer too much this week."

(Reporting by Andrew Both in Cary, North Carolina; Editing by Mark Lamport-Stokes)