Erriyon Knighton’s Twitter biography is short and to the point: “Professional track athlete.”

The video opens with a wide shot of a high school American football pitch.

Cheerleaders on the sidelines. A crowd of about 100 spectators in the bleachers. A Friday Night Lights scene.

A slender, rangy figure in home-team red gathers a kick return on his 10-yard line. He looks up, spots a hole in the onrushing defence and darts through, evading a tangle of limbs.

He hits halfway at a gallop. A final defender comes haring across, all pumping thighs and straining arms. But, it’s in vain. The home team holler on the touchline as their man’s easy, fluid stride eats up the field and carries him to the endzone.

It is just the start of a four-minute highlights reel, posted in June 2020.

And plenty were watching. Knighton’s speed, 6ft 3in frame, sure hands and aggression had the country’s best college football programmes – Alabama, Florida State, Tennessee and others – preparing offers.

But, as the pandemic bit, the points switched. Knighton was sent down a different path.

“It could have gone differently if high school season was still going,” he told BBC Sport. “I probably would still have been playing football if I would’ve had that extra year.”

Instead, as school gridiron grew cold amid an enforced shutdown, a 16-year-old Knighton focused on his side hustle: track.

He had been sprinting for a little over a year, after being encouraged to do so by his football coach as a way to sharpen his game as a wide receiver.

“I only started running track in the ninth grade,” Knighton remembered.

“Before then you could have asked me what 100m was and I wouldn’t have known. I knew nothing about track.

“By the end of that year, I realised that I was kind of separated from the pack and faster than most people.”

And they have never caught up.

Knighton, unable to compete locally because of lockdowns, took part in the nationwide Junior Olympics, just a couple of months after posting his latest football highlights video online.

Running in 200m against other 16-year-olds, he stormed home in 20.33 seconds. As you watch the footage, you can hear one voice from the stands swear in disbelief as the stagger unfurls and the extent of Knighton’s yawning advantage is revealed.

Only Usain Bolt had ever gone faster at under-18 level. Only three Americans of any age – Noah Lyles, Kenny Bednarek and Josephus Lyles – went faster that year.

From then on, Knighton was destined to be wearing spikes, rather than shoulder pads.

But his decision to turn professional in January 2021, still aged just 16, was a big one. He could no longer compete for his school. He could no longer take up university scholarship offers.

He was straying off a well-worn path to the top. There were murmurs that it was too much, too soon. Hubris fed by hype.

“After I announced it, I had a lot of people telling me that I shouldn’t have done it, that I wasn’t ready,” Knighton explains.

I take it they are not saying that now? Knighton just smiles.

In June, the then 17-year-old became the youngest American man to make a United States Olympic athletics team in 57 years.

In Tokyo, five weeks later, he finished fourth in the 200m, one place outside the medals.

That under-18 world record set by Bolt? Through the rounds and Olympic build-up, he beat it seven times over.

He’s a bona-fide breakout star. This summer, another stage beckons, a home World Championships in Oregon. But if Knighton runs like he is in a hurry, he knows he has time on his side.

“In Tokyo, I was kinda upset that I had lost, but I just had to think about the big picture and the long run,” added Knighton, who turned 18 in January.

“I get called young every day, I am going be 24 in 2028, that is in two more Olympics and still kind of young. I think about that all the time.

“That Tokyo experience is something no-one can ever take from you, I will always have that experience. I really try not to get caught up in the pressure.

“As I grow older I am going to get stronger and faster. I am not the perfect 200m runner, I am still learning as I run it.”

Knighton is still learning off the track as well. He is back in school, walking the corridors of Hillsborough High School in Tampa, Florida, brushing shoulders with current class-mates and former football team-mates. A little more money, a few free tracksuits, but still the same teenager.

“There were a lot of people wanting to take pictures with me at the start of the school year,” he remembers.

“I think I signed an autograph actually, it got that chaotic.

“It has calmed down now. Now everyone just walks past me just like, ‘Hey, Erriyon’.

“In other schools in the area, people say to my class-mates ‘you go to school with Erriyon’, but for people in my school they see me every day, so it ain’t nothing.”

They won’t be the only ones getting familiar with Knighton’s fame over the next few years.