Novak Djokovic, the world's top ranked male tennis player, is unlikely to be allowed into the United States for the upcoming U.S. Open tournament. This would be the second Major this year that he has missed, not due to injury or illness, but because of his vaccination status.

Djokovic has openly talked about how he is not vaccinated and acknowledged that he has no plans to do so in the future. That's obviously his choice. And he appears willing to deal with the consequences.

So, we thought it was worth diving into exactly why he is not being allowed to play in this year's tournament, as well as what it means historically.

Novak Djokovic not allowed to play 2022 U.S. Open

When COVID-19 hit the world in early 2020, the sports world was shaken just like everyone's lives. However, many of them figured out how to continue playing without fans. That happened during the 2020 U.S. Open, and Djokovic participated. He ultimately pulled out of the tournament due to injury, giving Pablo Carreno Busta a walkover victory.

The following year, Djokovic once again was allowed to play. The American government had a better handle on the global pandemic, but numbers were still there and people were still dying. This time, Djokovic made it all the way to the Final. But he lost in straight sets to Daniil Medvedev.

This year, Djokovic is not being allowed to play. That's because he is not being allowed into the United States. So what gives? Why can he enter and play in 2020 and 2021, but not this year? Many people have pointed fingers at the ATP, or the USTA, but the truth of the matter is it was never their decision.

The American federal government have since passed a measure that does not allow any unvaccinated non-citizen into the country. There are some exceptions, but a tennis player is not one of them, understandably. In typical fashion, tens of thousands of tennis fans have began putting a petition together.

But that is not likely to make much of a difference. Again, it's not the USTA making this decision.

One thing both the U.S. Open and the United States do not want to do is create the same fiasco seen earlier this year at the Australian Open. Djokovic was initially allowed into the country via an exemption. Then Australian courts overruled the decision. Meanwhile, the tennis legend essentially was held in a detention center for a few days while the process played out.

But if Djokovic is willing to accept the fact that he will not play in the U.S. Open, so should his fans.

What this means for Djokovic' legacy

For almost 20 years, the sport of men's tennis has been ruled by three men: Roger Federer, Rafael Nadal and Novak Djokovic. Never before in the history of tennis have three athletes dominated the way that these three men have. Between them, they have won 63 of the 74 Grand Slams since 2004.

Federer led the way for much of his career. But he's a bit older and his career slowed considerably, with his last Grand Slam title coming at the 2018 Australian Open. Entering 2022, all three men sat on 20 Grand Slam titles.

Nadal would take advantage of Djokovic' aforementioned absence at the Australian Open and capture his 21st title. He followed it up by winning the tournament he owns, the French Open. That put him at 22 and two ahead of the others. But Djokovic bounced back and captured his fourth consecutive Wimbledon title earlier this month, moving to 21.

Nadal was forced to bow out of his semi final match due to injury. It's not yet known whether he will be able to play in the U.S. Open either. But the fact that Djokovic is all but ruled out, hurts his chances of finishing atop the list. He's 35 years old and the Dominic Thiem's and Medvedev's are not going away as he gets older.

At this point, these three men have separated themselves from the field. Pete Sampras has the fourth most Grand Slam titles in the Open Era with 14.

But statistically, Djokovic might have the best case. He is the only player among the Big Three with a winning record against each of the other two. He is 27-23 vs Federer all-time and a narrow 30-29 vs. Nadal. But beyond that, he has spread out his championships among the different surfaces.

Arguably the biggest knock on Nadal as the greatest player of all-time is the fact that of his 22 Grand Slam titles, 14 of them have come at the French Open. He has only won the Australian Open and Wimbledon twice each. I know, that sentence is absurd but that's how great these guys are.

Whereas Djokovic has won seven Wimbledon titles and nine Australian Open championships. That's two different surfaces he's dominated on.

But none of those stats matter if Djokovic does not surpass Nadal in total Grand Slams. Federer and Nadal are considered the ultimate gentleman in a gentleman's sport. Novak Djokovic is the bad guy the media loves to dislike.