Sun is heading back to the Court of Arbitration for Sport next month for the next instalment in his drawn out doping case in a last ditch bid to be free to swim at July's Olympics.

The 24-year-old is on the Gold Coast ahead of this week's Australian swimming championships as he continues his own Olympic preparations.

Horton, who made global headlines after refusing to stand on the podium alongside Sun at the 2019 World Championships, will keep an eye on the progress of Sun's hearing but isn't stressing over the outcome.

"I don't follow it religiously but I will see whatever happens," he said.

"It doesn't really make that much of a difference.

"I focus on being the best swimmer that I can be and at the end of the day, it's really me versus myself as with every other athlete. It's all a head game."

Horton has become an ambassador for Batch Tested, an online platform that offers supplements and sports food that have been verified and screened for substances that may result in a positive doping violation.

In a world where Horton won't order a smoothie from a cafe for concerns about what is in it or if the blender used to make has had a prohibited substance in it beforehand, the peace of mind of ordering from a vetted source is invaluable.

Horton, who revealed he didn't undergo anti-doping testing for approximately nine months last year during COVID lockdowns, doesn't believe the global pandemic will impact on the integrity of competition in Tokyo.

"I don't think COVID is an issue in worrying about the integrity of the Olympics. I think the issue is different countries adhering to different standards, more than COVID being the factor," he said.

Australian Associated Press