From Brian Keogh in Pittsburgh

Padraig Harrington is bracing himself for a hair-raising, "Wall of Death" style white-knuckle ride at brutish Oakmont.

First to sign in on Sunday afternoon, Harrington got set to play his second practice round on the toughest US Open course of them all and confessed that he'd be happy to shoot four 72s - or eight over par.

While he's looking forward to the challenge, the Dubliner is predicting mayhem on the famously undulating greens at the punishing Pittsburgh track.

In fact, some of the green are so tough that the European No 1 reckons TV viewers will get to see players missing greens with their chips!

Explaining the difficulty of the test, he said: "I'll tell you want you'll see this week. You will see a lot of guys miss greens and chip it away from the pin.

"They'll chip it 40 feet past the pin to run it back to the hole. You will see a lot of 'Wall of Death' shots.

"That means that if you are on the wrong side of the 'Wall of Death' you will see a lot of guys chipping from beside the green - and not getting on the green.

"That will happen an awful lot. And guys chipping from awkward spots will be able to chip away from the pin and get it to run backwards."

Missing the cut in the Stanford St Jude Championship in Memphis gave Harrington the chance to play 18 holes at Oakmont on Sunday and another nine yesterday.

And after getting a taste of what's to come, the world No 11 had no problem describing the course as the toughest he's ever seen.

He even went as far as saying that the course is so tough that the USGA could take the week off and the players would still struggle to shoot level par.

He explained: "If it was hard and fast with no rough it would be a fantastic, enjoyable fun test. But it will be difficult. I’d certainly take four 72s now and I don’t know any other tournament where I’d take eight over par starting off.

"It must be the toughest test ever, bearing in mind it is very warm, not long and it is not that windy. Most golf courses rely on length or adverse weather conditions, but this is lovely. It is not brutally long.

"I’d say I am looking forward to the challenge and I've got a few days to get things right. But I don’t think I have seen consistently as much trouble on the right edge and the left edge of fairways.

"Normally you might have a bunker on one side or water on one side and rough on the other, this has two sides of the fairways with trouble."

Apart from the bunkers and the rough, the greens are what makes Oakmont the toughest US Open course of them all.

And they are so undulating, they actually remind Harrington of hilly Stackstown - the Dublin course where he grew up.

He said: "The greens are obviously the difficulty, though. There’s severe sloping, remind me of the early days of Stackstown. Eight or nine greens you couldn’t stop the ball if you were past the hole, they’d run off the green.

"It’s been a long time since I’ve been on that. It's very severe. They’re already struggling to find pin positions and they’re due to get the greens firmer. To be honest, they don’t need to do any of that to get level par as the winning score.

"It’s got everything to make it tough. It is tough with hazards off the tee. It is tough with rough off the tee. It is tough with rough around the greens. It is tough with the pin positions. It is tough with the slope on the greens, and it is tough with the pace of the greens. It makes Winged Foot look benign."

Even the bunkers are tough, as Harrington discovered in the practice area yesterday.

As he worked on sand shots from plugged lies, the Dubliner SHANKED twice and thinned another one over the back of the green, forcing one of the amateur qualifiers to take evasive action.

The greens, however, are the big test and while there are reports that they are measuring 13 on the stimpmeter, Harrington believes they could get even faster than that.

He said: "You have to measure on a flat spot and there are a number of greens that don't have 13 feet of a flat spot.

"The flat ones are 13 and a half. But poa annua is faster downhill than bent. So they can tell you it is 13 and a half flat but the ball sits on top of poa annua.

"They are good to putt on, no problem there. But they are difficult for everybody.

"The problem is there is no middle of the greens. There is a number of holes you can’t hit it in the middle of the greens. It isn’t there. Like, the second hole the middle of the green the ball would come back. There’s a few holes you’re forced into going at the pin rather than anywhere else.

"There is a number of pin positions you play safe and you’ll run off the greens, so a lot of them will force you to go at them. You’ll see a lot of guys in bunkers rather than rough this week."

The challenge is so tough that Harrington reckons it will be possible to short side yourself even if you hit the green.

He said: "I don't think at this level that we can afford to miss a green, at all. The pins are going to be tight, the greens are fast and you might be chipping otu of four inch rough.

"If you are chipping out of the rough and up a tier and down a tier, that needs to be a delicate shot. And while I feel that I am as capable of playing it as anybody else, I just don't feel like it is a shot you want to leave yourself."

Staying out of Oakmont's 180 bunkers is another challenge that Harrington doesn't fancy too much either, especially if he ends up in the face of one.

He explained: "They are all about seven of eight feet high and you need to be about 12 feet from the top to that to get an eight iron out.

"So if you are in the middle of the bunker you can hit eight iron and even seven iron out of them. They are not all penalties and there are times I'd rather be in the bunker and times I'd rather be in the rough.

"But I'd never want to be anywhere near the face of a bunker because they are all about eight feet high. If you are anywhere close to that you are just hitting it 40 or 50 yards."