Nor should anyone be surprised when Nadal hands Murray yet another defeat in their increasingly lopsided rivalry to advance to the final of the year's Grand Slam finale.
Granted, any victory for Nadal will be hard-fought, earned on the hard court at Arthur Ashe Stadium with the blood, sweat and tears of a man who has spent more time battling his own body in this tournament than he has the efforts of his opponents.
On Friday, though, it was Nadal's opponent, Andy Roddick, who was caught in a losing fight against his failing health. Nadal showed little sympathy for Roddick's bum left leg and poor conditioning, ousting America's last hope for a homegrown national tennis champion with almost alarming ease, 6-2, 6-1, 6-3.
Alarming for Murray, that is.
The fourth-seeded Scotsman took out an American of his own, 28th-seeded John Isner, in four sets on Friday, 7-5, 6-4, 3-6, 7-6 (7-2). The crafty Murray withstood the 6'9" Isner's powerful serves with passing shots and lobs to make it four-for-four in semifinals reached at Grand Slam events in 2011.
Saturday's match will mark Murray's third in a row against Rafa in a Grand Slam semifinal this year, with Nadal claiming victory at the French Open and Wimbledon. Murray has yet to win a tennis major but has come agonizingly close this season, with "agony" being the operative word for what he's likely to feel by the close of play on Saturday evening.
Who will advance to the final?
Nadal has owned Murray in their head-to-head series, and even that's putting it lightly. In 16 previous meetings, Rafa has come out ahead 12 times.
There's a reason for that advantage, of course. Nadal is known for being aggressive and unrelenting, putting forth only the highest degree of physical effort against his opponents while putting his health at risk in pursuit of intimidation and on-court dominance.
Murray, on the other hand, has a reputation for being "soft," someone who's more prone to playing a passive, defensive game, utilizing his counter-punching expertise and superior intelligence rather than asserting his will.
That trend isn't likely to change by Saturday afternoon, when Murray is set to meet Nadal at center court in Flushing Meadows. Murray's best bet, at this point, is to hope that Rafa's body will break down by virtue of playing his third match in as many days.
Which is to say, Murray's chances of moving on to the final are slim to none. Murray will put up a fight, he'll push Nadal and make the match competitive, but he will need something of a miracle to withstand Rafa's power and keep him from defending his US Open title.