As is the case any week on Tour — especially leading up to the majors — the bulk of popular and media attention is directed toward the top players. The favorites, naturally. And that’s as it should be.

But often enough, that pre-tournament adulation heaped on the Tiger Woods, Rory McIlroys and Phil Mickelsons of the world dissolves in a haze of bewilderment. In recent years, the likes of Lucas Glover (2009), Ángel Cabrera (2007) and Michael Campbell (2005) have left the golf world shocked to see a winner no one saw coming. Might the 2013 edition of the U.S. Open furnish a similar surprise? The answer is that paradoxically, a surprise winner of this year’s tournament at Merion should not surprise us at all. Here’s why.

The Venue

The potential for an upset U.S. Open champion begins with this year’s site: Merion Golf Club, located in suburban Philadelphia. You have probably already heard enough about Merion’s modest length — at 6,996 yards, it will be the shortest U.S. Open site since Shinnecock Hills in 2004 — and that is an important part of the equation, since it gives everyone in the field a chance to compete and maybe win. On most holes, players who average more than 300 yards off the tee will be playing from the same spots in fairways (or roughs, or hellish bunkers) as those who drive it closer to 260. This levels the playing field tremendously where in past years, 7,300-yard-plus major championship sites have disproportionately favored longer hitters (recent major champions Martin Kaymer, Rory McIlroy, Keegan Bradley, Bubba Watson and Ernie Els all can bomb the ball off the tee).

Another factor to consider is communal unfamiliarity with the course. No one in the field played in the last U.S. Open staged at Merion — 1981 — and only a handful competed in the 2005 U.S. Amateur. Add that to troublesome weather on Monday that hindered some practice (more on that momentarily) and you have a relatively less-prepared field who could fall victim to some of Merion’s smoke and mirrors.

The Weather

On top of rendering Merion soggy beyond any hope of ideal, firm-and-fast playability for the 2013 Open, Mother Nature has brought more of the field into the tournament. Because the softer ground conditions will remove some course management strategy in favor of a heightened demand for pure execution, a streaky longshot could get hot and ride that momentum to a surprise major championship triumph.

The Moment

It’s what will make even casual viewers’ hearts pound late on Saturday and all day Sunday. It’s major championship pressure and it can get to anyone. Important to note is that pressure often hangs thickest on the backs of the more-heralded players. In 2009, a 50-to-1 longshot called Mine That Bird won the Kentucky Derby, and Churchill Downs’ announcer barely had the chance to say the horse’s name before he had crossed the finish line. Similarly, players like Ben Curtis in the 2003 British Open and Geoff Ogilvy in the 2006 U.S. Open have come in under the radar in major championships while the spotlight blinds those of whom the most is expected.

So who could win this week that we have not heard much about? Here are three candidates:

Tim Clark

The winner of the 2010 Players is one of the shorter hitters in the game and while he has one significant win to his credit, he is far from most people’s favorite. But he is a very good ball-striker and is gritty, with plenty of Presidents Cup and previous major championship experience to support his claim. He is paired with friends and fellow South Africans Louis Oosthuizen and Charl Schwartzel for the first two rounds as well. Some stars have aligned for Timmy already; will he show the rest to us come Sunday?

John Senden

Like Clark, Senden is paired with two countrymen in fellow Aussies Marc Leishman and Marcus Fraser. That’s a good start. Even better: Senden is one of the game’s best ball-strikers and should be playing from the fairways and greens more often than much of the rest of the field. He is a streaky putter at best, though, and could be confounded by Merion’s fearsome putting surfaces. But if they prove a menace to everyone else and Senden merely stays afloat on the greens, look out for him.

Jamie Donaldson

You could argue that calling a player in the top 40 in the world (he’s No. 39) a dark horse might be a stretch. But Donaldson is possibly the least-known player in the top 50, so much so that it would be understandable for you to fact-check me on his Official World Golf Ranking right now. But it’s true, and Donaldson finished gamely — tied for ninth — in last year’s PGA Championship at The Ocean Course, which offered a U.S. Open-stiff challenge to everyone not named Rory McIlroy. Donaldson’s two European Tour wins have come in big events: the 2012 Irish Open and the 2013 Abu Dhabi HSBC Golf Championship. Keep an eye on him this weekend.

Have any other late-breaking underdog picks for this year’s U.S. Open? Let us know in the comments.