Can Isner give U.S. more Davis Cup magic?

John Isner is halfway through what could become one of the greatest 12-month individual Davis Cup performances in history, and the hard part isn't necessarily still ahead -- difficult as that may be to believe.

The tie between the U.S. and Spain begins Friday in the coastal, industrial city of Gijon (home to, among other things, the International Bagpipe Museum -- take that, U.S Open champ Andy Murray!). The surface is on outdoor red clay, and Spain is led by ATP No. 5 David Ferrer and No. 10 Nicolas Almagro.

Those two have bagged six clay-court titles between them, which is five more than the U.S. singles players, Isner and No. 22 Sam Querrey. Did I mention that the six clay titles is just in 2012, while the lone title the Americans have managed is a career number?

So Spain is clearly the favorite. The only match you can tentatively mark as a W for the U.S. is in doubles. Mike and Bob Bryan, who just equaled the all-time Grand Slam doubles title take of Mark Woodforde and Todd Woodbridge (11 majors), are Davis Cup studs, having amassed a 20-2 record over years of diligent service.

But here's the curious thing: This year, Isner already has beaten Roger Federer, Jo-Wilfried Tsonga and Gilles Simon on red clay. And he triumphed over them on their respective home courts. (He also had a dead-rubber win over Marco Chuidinelli of Switzerland.) When it comes to quality wins, Ferrer and Almagro certainly are no more formidable a twosome than Federer and Tsonga.

Don't bother trying to figure how we got to this point. This is Davis Cup, an event that has shown, time and again, that you can throw the form chart right out the window. Some players are just cut out to be Davis Cup warriors; others never quite get comfortable with the unique team competition, mainly because playing for your country triggers a different kind of pressure than does regular tournament play. The Davis Cup mystique is also self-perpetuating.

Here's another thing that must encourage U.S. captain Jim Courier, Isner and company: Rafael Nadal isn't in the Spain lineup. The undisputed capo of the Spanish team, it's hard to gauge what effect his absence will have on the red-and-gold side.

Four years ago, Spain recorded one of the great upsets in Davis Cup finals history without help from Nadal. Fernando Verdasco and Feliciano Lopez combined to win that tie on hostile turf in Mar del Plata, and note that the only match Argentina won on the hard courts was the first one when David Nalbandian upset Ferrer.

Like I said, in Davis Cup, you can't just go by ranking and previous records. Ferrer had been 6-3 against Nalbandian before that tie. Team USA has surpassed expectations so far this year, and there's no reason they can't continue to do so. Team chemistry is an important aspect of Davis Cup, and Captain Courier seems to have settled in after four ties (3-1) as a natural leader who has managed to bring the best out of his players.

One of the often-overlooked aspects of Davis Cup is that as daunting as it may be for a visiting team to face the often rabid, chanting, stomping, borderline out-of-control crowds they meet, the real pressure is on a home team, at least when that squad is favored to win.

Courier and his team can basically adopt a roll-the-die attitude and let Ferrer, Almagro and company (the other two members of the Spanish team are Marcel Granollers and Marc Lopez) sweat it out without being able to rely on the leadership -- and clay-court invincibility -- of Nadal.

Spain is the clear and obvious favorite, but Isner is on a Davis Cup roll, and if he can continue it, the U.S. team might leave Gijon humming the tune so popular with fans of the bagpipes everywhere, "Amazing Grace."