Barry Hearn has warned KSI to expect to lose money at Dagenham, but told the YouTuber that football could give him some of his happiest times ahead of Saturday's FA Cup clash.
Veteran sports promoter Hearn invested in seventh tier Brentwood Town this summer and will hope his Isthmian Premier club pull off a shock in the third qualifying round of the FA Cup when big-spending Dagenham visit The Arena.
The BBC cameras will be present to witness the clash with the Daggers, who boast KSI as a shareholder and have former England forward Andy Carroll in their ranks.
Matchroom president Hearn spent nearly two decades as Leyton Orient chairman and has worked across a range of sports including boxing, darts and snooker.
During a week where his son Eddie Hearn helped bring Anthony Joshua and Tyson Fury face-to-face and Manchester City were found guilty of breaching Premier League rules, Hearn cannot wait for FA Cup fever to hit Brentwood.
"This is a massive game and I think the Manchester City saga sort of exemplifies the difference between professional sport and amateur," Hearn told Press Association.
"Dagenham coming over, obviously KSI with his involvement there. I mean, look at some of their players, in particular their centre forward who's rather famous. Yeah, it's a bit scary, but then you look, the bigger picture is the excitement of being involved in the day.
"For Brentwood Town, whose average gate is probably 750, this is a big day out. It puts Brentwood on the map."
Hearn was born in Dagenham and wishes KSI all the best at the National League South club.
"Look, it is the worst business in the world. It's a completely flawed business in a normal business sense, because it's not normal," Hearn said.
"KSI will have a dream for where he wants to see Dagenham & Redbridge. I wish him all success, not on Saturday, but in his following his dream and his love.
"It'll cost him money. He will get abuse, but he will have one or two memories that will repay him back the rest of his life.
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"I've had a fascinating life and a wonderful time in sport, but when I go upstairs -- and hopefully in some many years to go -- at least five of my top 10 memories in my life will be football related, which is remarkable when you're putting in all the thousands of athletes I've looked after, the tens of thousands of events I've staged.
"When Orient equalised against Arsenal in the FA Cup [in 2011.] It's one of the greatest days of my life.
"And the whole principle of the FA Cup is what sport should be about. There are no barriers to entry. It doesn't matter who you are, whether you're Manchester City or whether you're Brentwood Town.
"It creates memories that you'll never ever forget. We may have a memory for kids on Saturday. Brentwood against Dagenham & Redbridge may create one of those moments that they never forget."