Internet sensations ‘KSI’ and Logan Paul will enter the ring for their first professional boxing match Sunday 4am (GMT) at the Staples Center, Los Angeles.
But chairman of Larches and Savick ABC Boxing Academy, Joe Kilshaw, says the fight undermines boxing and disrespects professional fighters who have been fighting for years.
The YouTube stars fought each other for the first time in an amateur bout at Manchester Arena last August which resulted in a majority draw.
But this time they have gone professional, which means 10 ounce gloves and no head guards.
The YouTubers – who have a combined following of over 40 million – will fight in front of an expected sell out crowd of 21,000 at the Staples Center. Millions more will watch on pay-per-view television
However, the fight has received some criticism as it will headline a bill also featuring British undefeated WBO super-middleweight world champion Billy Joe Saunders and American WBC lightweight champion Devin Haney.
Gym owner Kilshaw believes the fight is an insult to professional boxing.
He said: “It’s not real boxing, people think it is but it’s not.
“There’s kids at my club getting punched in the head and they [KSI and Logan Paul] are getting paid millions for this fight.
“If they put back into community boxing, taking kids off the street, then fair enough, but they won’t.
“It’s white collar stuff. It’s a grade below amateur boxing.”
However, the YouTube stars aren’t the first celebrities to enter the ring.
Preston-born cricketer Freddie Flintoff traded his cricket bat for boxing gloves in 2012 where he defeated inactive professional boxer Richard Dawson on points, despite being floored in the second round.
Comedian Lee Evans began life as a boxer at Thurrock Art College before following his father Dave into the entertainment industry.
And comedian Ricky Gervais was victorious in the ring against British businessman and television personality Grant Bovey, winning the bout on points.