Until now, 2017 was shaping up to be maybe the best year for boxing of the 21st century. All of that changes Saturday.

No matter what happens in the T-Mobile Arena outside Las Vegas, the mega-hyped Floyd Mayweather-Conor McGregor circus almost certainly will thwart a year for the ages. McGregor not only doesn't belong in the same ring as Mayweather, but he also doesn't even belong in the same sport.

One of two things is going to happen in this fight: Either Mayweather will decide he doesn't really want to fight and plays pattycake all night, or he is determined to prove a point and dismantles McGregor.

Either way, it will be horrible. I for one won't be watching.

If McGregor is fortunate enough not to suffer any permanent injury, the willingness of one of boxing's greatest-ever welterweights to step into the same ring with him will inflict a deep and lasting bruise on a sport that always had lived on the periphery of respectability. Mayweather is a confirmed creep, but now he is shamelessly tarnishing his sport's reputation for the naked greed of another monster payday.

Being a boxing fan, as I've been since I was a boy, is tough. You're forced to withstand a legacy of fight-fixing, judging that is at times horrendous, and a cast of shady characters worthy of the tawdriest Mickey Spillane novel.

But the sport is also beauty, a marvelous spectacle of one-on-one fight-against-flight and a "sweet science" that demands a stunning level of skill and stamina, and occasionally some showmanship.

I don't mind the show. Muhammad Ali and Sugar Ray Leonard and Roberto Duran and a host of other great fighters through history brought not only mad skills but also an ability to showcase them that made the sport exciting and fun.