The 44-year-old boxing legend made his sensational return to the squared circle against Paul at the Hard Rock Stadium in Miami, Florida.
Mayweather, who retired undefeated with an unblemished 50-0 record, largely dominated the 26-year-old American over their eight-round exhibition clash earlier this month.
However, the former five-weight world champ went the full distance with Paul, despite knockouts and stoppages permitted as per the official rules.
Mayweather was heavily criticised for failing to knock out Paul, but the American superstar was unfazed after claiming he made an eye-watering $100m from his exhibition fight.
Paul vs Mayweather's exhibition showdown was a blockbuster hit as well, with UFC president Dana White confirming it did a million pay-per-view buys.
Khan, who long sought a clash with Mayweather, has claimed that he is "not really a big fan of that exhibition thing."
The 34-year-old Brit added that people aren't "taking boxing seriously" and a "lot of people said Floyd didn't look the same."
Speaking on the Last Stand Podcast with Brian Custer, Khan said: "I'm not really a big fan of that exhibition thing.
"No disrespect to Floyd or the other fighters that are doing that, but I just think it's not good for the sport of boxing.
"People are not taking boxing seriously and boxing's a sport where, the time they are going to start taking it seriously, is when someone gets badly hurt.
"We just don't want that to happen and I think it would be quite tarnishing for boxing if God forbid a YouTuber got knocked out by a professional fighter.
"You can't really compare the two. I would never do that because I would be scared to hurt someone and if you hurt an influencer and you are the fighter that people always respected, you're going to lose that respect.
"Really, you shouldn't be sharing the ring with that person. Floyd did it a couple of weeks ago in Miami the other day against Logan Paul.
"He couldn't hurt Logan and it looked bad for him. Him being a trained professional fighter for many years, whereas Logan came, put his gloves on and went in the ring.
"A lot of people said Floyd didn't look the same. Really, he got more bad comments than he got good comments in that fight.
"Did he really need the money? No. We don't think he does. But going into that fight he got a lot more hate because he couldn't knock out a guy who's worse than a journeyman basically."
Chosen for YouChosen for You
Most Read StoriesMost Read