Zion Williamson can become the best player in the world and will enjoy the challenge of stepping up to the NBA, according to his old high school coach.

Duke's 6-7, 285-pound forward Williamson is perhaps one of the most high-profile athlete ever to come through the American collegiate system, a player whose fame means he is recognizable by his first name alone.

The hype surrounding him — which has been fueled by a series of monstrous dunks and highlight-reel plays — is akin to the excitement that surrounded LeBron James before he entered the NBA in 2003.

Except Williamson's story is playing out in the social-media age. The 18-year-old already has almost three million Instagram followers and his presence on Duke's team meant the cheapest available tickets for their contest with North Carolina in February cost $2,500. 

He has come a long way from the 11-year-old that his future Spartanburg Day School coach Lee Sartor first encountered.

"He was learning the game, but you could just tell from a basketball-IQ perspective that he was just a little bit ahead of the other kids," Sartor told Omnisport. "He was just an average height of a fifth grader, nothing overwhelming."

 
 
 
 
 
 
 
 
 
 
 
 
 

#3peat Couldn’t think of a better way to end my high school career. Built a lot of friendships over my four years @spartanburgday time really does fly. Proud to say I was a Griffin

A post shared by Zion Williamson (@zionlw10) on

Sartor got a closer look when he worked Williamson out ahead of his ninth-grade year in South Carolina — and it was there that he first asked him to dunk.

"One drill was just a simple drill where he would attack the basket from the wing area going to the baseline," he explained. "I remember asking him if he could dunk. He said, 'I think so.'"

That feat became much easier when he grew to 6-3 as a 15-year-old in ninth grade, when his physicality started to set him apart.

"He was always an engaged player, a perfectionist," Sartor added. "He wanted to make sure he mastered a drill. He was driven, very self-motivated. Didn't mind working hard. He was the first person in the gym and the last to leave.

"As he got older and started getting taller and gaining mass, he was not only the best player from an IQ perspective but physically he was just dominating. I remember sending one of his dunks to ESPN and it ended up in the top three. Of course, with social media he started blowing up on the internet. We kept sending in his plays and they were posted on YouTube. It ballooned up to where he had millions of followers.

"Our games started selling out. I knew that Zion had arrived when we went to Illinois, which is several states over, to play in a Thanksgiving tournament and all of those games had sold out. Everybody just wanted to be able to witness his greatness."

Soon those attending NBA games will be able to witness Williamson too, with the Blue Devils forward anticipated to declare for the 2019 NBA Draft after one year at Duke and become the first overall pick later this year.

Williamson will be expected to transform the fortunes of whichever NBA team he ends up on — a challenge Sartor feels he is ready for.

"We haven't seen the best that he has to offer yet because that moment hasn't happened yet," he added.

"I think the more he's challenged, the higher the level he will rise to. ... The first time I worked him out I told him he could be the best player in the country as a high school player. If he continues to work hard and God blesses him without any injuries, I think he's got a chance to be the best player on the planet one day.

"There are players that come along once in a lifetime — a generational player, that transcend(s) the game. And what he brings to the game is unique. I think Zion is that player for now."