Rafael Nadal has already beaten Andy Murray in two Grand Slam semi finals this year and the problems the Brit is having with his first serve at the US Open means that Nadal can complete a hat-trick.
Nadal won in straight sets at the French Open and then followed up to prevail in four sets at Wimbledon, while he was invincible when thrashing Andy Roddick in the quarter finals of the US Open this year 6-2, 6-1, 6-3.
It is 2/5 in the US Open tennis odds that Nadal triumphs again and the way the match pans out will largely depend on how well Murray serves.
Problems with his first-serve percentage have already resulted in Murray being broken by far weaker players than Nadal in this tournament, but he has had the stroke play and ability to battle back.
This may prove far tougher against Nadal, who is not only more likely to capitalise on any errors, but also be less giving when it comes to allowing Murray to break back.
If Murray does struggle with his serve, which is even more likely if the wind picks up at Flushing Meadow, then Nadal could be a fantastic price at 15/8 to win in straight sets.
Although Murray has lost four of his 16 previous meetings with Nadal, his variation has been known to cause the Spaniard problems.
At the French Open, Murray had 18 break point opportunities against Nadal, while at Wimbledon he played virtually perfect tennis to win the opening set before seemingly falling apart.
Meanwhile, he did win on the only previous occasion that he has faced Nadal at the US Open, which was also ironically in a semi final in 2008.
Murray is particularly confident he can beat Nadal on a hard court and is 2/1 to move into the US Open final.