Floyd Mayweather, Jr. may be the world's undefeated champion boxer, but his supposed difficulty in reading is his Achilles' heel, as some reports claim.

Recently, 50 Cent's ALS Ice Bucket Challenge video brought up his long standing feud with the boxer and a radio station provided more evidence to show that Mayweather has reading problems.

According to the NY Daily News, "The uppercut of audio was prompted by rapper 50 Cent's takedown of Mayweather Thursday on Instagram. Fitty lampooned the viral ALS challenge, saying he'd donate $750,000 to a charity of Mayweather's choice if the tongue-twisted pugilist could read just one page of ‘Harry Potter.'"

Over Instagram, 50 Cent posted a video clip challenging the athlete. "This is a special ASL-ELS challenge for you, Floyd. If you can read one whole page of a Harry Potter book, I'll give $750,000 to whatever charitable organization you choose." 

To add insult to injury, on Friday morning, Power 105 DJ, Charlamagne Tha God, released an embarrassing recording of the boxer struggling to read a few simple sentences. The 37-year-old sounded completely out of his element as he tried to to read a radio "drop" between segments on WWPR (105.1 FM).

The audio clip begins with: "I'm Floyd Mayweather," and he stumbled for a few minutes. He found the line "movement to support hiring vets" specifically trying.

Explaining the decision of the station to release the clip, Charlamagne says, as quoted by HuffPost, "I got nothing but respect for Floyd Mayweather. He's the greatest defensive fighter of all time, but I got a show to do," said the DJ. "I gotta sell tickets too, baby. Just like he likes to put on a show, I like to put on a show to. This is for our listeners' benefit."

Mayweather has been particularly quiet but he managed to post over Instagram, his simple response. He posted two cheques issued to him by Golden Boy Promotions, LLC, amounting to $31,406,000.00 and another $40,870,000.00. 

It might be a reminder that even if he can't read well, he's still filthy rich. Mayweather captioned the pic: "Read this $72,276,000.00. God bless."

The following day, Jimmy Kimmel offered to let Mayweather read on his show.

Mayweather grew up during hard times in Grand Rapids, Mich. With both parents struggling with drugs, Mayweather dropped out of school to puruse boxing, recalled NY Daily News. 

"I knew that I was going to have to try to take care of my mom and I made the decision that school wasn't that important at the time and I was going to have to box to earn a living," Mayweather said back in 2007. 

Listen to the clip below: