"I cant say I'm a fan of it", Hatton told BBC Radio 5 live's Sportsweek programme.
"When you have a Muay Thai fighter in Thailand, they make their career and then they jump into global boxing and many have been very successful", he added.
Based on the current odds, McGregor is being given a better chance at beating Mayweather than previous Floyd opponents Marcos Maidana, Miguel Cotto, and Victor Ortiz.
"I feel embarrassed to say this but I'd be very surprised if [McGregor] wins a round", said Hatton.
Turkish leader's security officers charged with assault in Washington
Mahmut Sami Ellialti and Ahmet Cengizham Dereci face charges of felony assault with significant bodily injury. Men in dark suits and others were recorded repeatedly kicking one woman as she lay curled on a sidewalk.
I'm not entirely sure who these people are, but they're out there somewhere.
The fight will take place in Las Vegas under normal boxing rules, despite McGregor having never boxed on the professional circuit, and will be contested at 154lbs.
"I was in retirement, but people wanted me back so I'm back."".
Speaking about the fight today, UFC boss Dana White insisted he believes McGregor will become "the biggest star in sports ever" if he manages to do the unthinkable on his pro boxing debut. "I think it could be a 12-round onslaught".
He added: "I'm not against sanctioning it for something like the Diamond title". It's two different sports.
So after months of going back and forth, it's all the more surprising that Mayweather's initial comments following the fight's official announcement this week were relatively mild, even respectful of his MMA-trained opponent.