Floyd Mayweather Jr. threw another verbal jab at Marcos Maidana, saying that the Argentine cannot knock opponents out using legal gloves.

Mayweather played down Maidana's impressive knockout win percentage, insisting that the former WBA welterweight champion won 31 fights via knockouts because of using non-padded gloves.

The reigning pound-for-pound king threatened to back out of their first showdown in May when Maidana's camp insisted that they should be allowed to use their usual gloves - a pair of Everlast MX gloves that has less padding around the knuckles.

"It's obvious he's been getting a lot of knockouts by fighting with gloves with no padding, which I don't feel is safe for me or for him," Mayweather said via BoxingScene. "Both fighters should be safe and be protected, even though it's a brutal sport. This is not a bareknuckle brawl, this is not MMA. This is about professional boxing at its highest."

Reports indicated that the issue about the gloves to be used in the upcoming rematch was not mentioned during the negotiations for the second fight.

Maidana and his camp have been making a strong push to convince the promoters to allow them to use the controversial Everlast MX gloves, but Mayweather insisted that his opponent cannot use the non-padded gloves.

"In the sport of boxing it's all about protecting both parties," Mayweather said. "Life after boxing, I care about my life after boxing. It's about being on an even playing field. Some fighters in the past, some fighters have died in the ring from gloves that wasn't padded. The only thing I want to do is be on an even playing field."

Maidana, who gave Mayweather one of the toughest fights of his career, said that the gloves that he used in the first showdown made him feel uncomfortable.

But if Mayweather's camp forces them to wear it again in the second showdown, the 31-year-old Buenos Aires native said that it will be a different story this time because he will have an opportunity to make himself familiar with the gloves.

"The gloves didn't feel comfortable, they felt like pillows," Maidana said. "It's an open issue. We're going to fight for my gloves. He probably won't want me to wear them, and if I have to wear different ones I will. At least I will have an opportunity to train in them this time."