The man who stunned the athletics world with his exploits at London 2012 is having to put his training on hold while a group of NBA hopefuls huff and puff their way around the circuit.
James himself was just a teenager when first he won the world title in 2011, and then followed it up by becoming the first Olympic medalist from the Caribbean island of Grenada.
Just as he took that unexpected success in his prodigious stride, during this brief break from the searing Tuscaloosa heat the runner is more than happy to chat at length about his other passion: Soccer.
"What do you think about Wayne Rooney? He's not a midfielder!" he tells CNN. "Don't play him at all if you're going to play him there," he says, answering his own question.
While new Manchester United manager Jose Mourinho will have to tackle the dilemma of the England captain's future role when the English Premier League season kicks off next month, James is laser-focused on his imminent date with destiny at the Rio 2016 Games.
The big question is not just if the 23-year-old can retain his title, but if he can break the world record set by American legend Michael Johnson in 1999.
James is unbeaten this year with six wins from six races, setting meeting records in four of them. His personal best is 43.74 seconds, still some way off the American legend's leading 43.18 -- and also his Olympic milestone of 43.49.
Johnson has spoken in glowing terms about James, but has also questioned his technique.
That constructive criticism, however, has not phased James' unflappable coach Harvey Glance, himself a former Olympian who won relay gold for the U.S. as a sprinter in 1976 and twice equaled the 100m world record.
"Kirani's kind of a victim of his own success in the fact that he's doing it young, and when Michael set the world record, Michael was 32 years old. Kirani's got nine more years before he can even reach that age, so let's put that in perspective," Glance tells CNN.
"Michael is a perfectionist and like most people are when they're world record-holders, we want everything to be perfect, we want everything to be fine.
"I understand that there is some clean-up that Kirani had to make, and he's made that. They call his finish 'rugged,' they call his finish 'a little bit unorthodox,' but I call it a finish.
"I don't make it any more difficult than what it really is. He finished with the best of them. Can he get better? Sure, he's 23 years old. Will he get better? Yes he will."
When it comes to breaking records, James has significant history.
At the age of 14, he won gold in the 400m at the 2007 CARIFTA (Caribbean Free Trade Association) Games in the under-17 category with a time of 47.86.
Two years later, at the same event, James ran a then personal best of 45.45 seconds, which not only set a new championship record, but also beat the six-year-old mark held by superstar Usain Bolt in the process -- a fact not lost on the modest Grenadian.
"Breaking Usain's record at the CARIFTA Games was something that I had as a goal growing up," he says during the interview at Glance's home in Alabama, where he has been based since accepting a scholarship at UA.
"It was a double win in terms of breaking the record and having Grenada finish one and two in the 400m. I think that was a very special moment, not just for me but for Grenada."
Having made history with a 200 and 400m double victory at the 2009 junior world championships, James made his mark on the senior stage two years later when he shocked defending champion LaShawn Merritt to win the 400m crown in Daegu, South Korea, timing his run to perfection.
With a time of 44.60 seconds, he set another personal best as, aged 18, he became the event's youngest winner.
"At the end of the day, all I try to do is just try to represent my country well," James says of the impact his heroics had on his fellow Grenadians, whose population numbers just over 100,000.
"I just try to instil pride in everyone that's affiliated with my country and myself."
If the 2011 world championships final was close-run, the 400m decider at the London Olympics later pretty much turned into a procession with 100 meters to go, as James conquered the field with ease to become the first non-American to beat 44 seconds.
"Winning gold at the Olympics, I think, was a very historic moment for my country, for myself," James says.
"Just going into those Games, all I wanted to do was perform well, to represent my country well. I think just having that mindset kind of allowed me to go about competing without having much stress on me.
"It was just a great feeling, and it filled me with pride just to be out there and to compete and to have our national colors on. It's something that I will cherish every day of my life."
James' compatriots clearly cherished what he managed to achieve in London, taking to the streets of Grenada to celebrate.
One such supporter was his own mother, though the dutiful son's first phone call back home after taking gold did not go quite to plan.
"I called my mother and she was out in the streets along with everybody else," James explains. "All I could hear was celebrations in the background, I couldn't hear her because there was so much noise.
"I guess she just kept handing the phone to various people. Either that or they were grabbing the phone from her. I think that's when it really hit me that I did something very extraordinary for my country."
Looking ahead to his Brazilian mission -- the 400m final is on August 14 -- James is coy when asked about the sort of time he could run, with 2008 champion Merritt among his rivals after winning the U.S. Olympic trials, along with 2015 world champion Wayde van Niekerk of South Africa.
"Anything could happen -- the weather could be perfect or it could be raining," he shrugs.
He's more vocal, though, in offering support to the beleaguered host city -- currently facing a range of issues including the Zika virus, crime, construction and pollution problems -- saying that Rio "won the Games for a reason because the Olympic committee saw something special in them."
And he is hoping to again show the world something special.
Unlike those high school kids momentarily halting his training session back in Tuscaloosa, James has no intention of being schooled in Rio.