Roger Mayweather is a former world champion boxer who also trained his nephew, Floyd Mayweather Jr. Greg Doherty/Getty Images

Former world champion boxer Roger Mayweather, also the uncle of Floyd Mayweather Jr., has died at the age of 58.

Roger was in declining health prior to his death, TMZ Sports reported on Tuesday. Mayweather reportedly died in the morning.

Roger fought in the featherweight, lightweight and welterweight boxing classes and was 59-13 in his pro career, which spanned 1981-1999. He was a world champion in the super featherweight, light welterweight and welterweight classes.

His nickname was the “Black Mamba” — yes, he held that nickname as a boxer well before Kobe Bryant adopted it.

“It’s funny because I wanted a boxing nickname that wouldn’t be common to most people. One day when I was flipping through channels and I came upon this channel showing different reptiles, and they were showing the black mamba, one of the most deadly snakes in the world. I loved the way the mamba attacked so quietly, but when he hit you he just hit you one time and the poison was in you. That reminded me of myself right there,” Roger said of the nickname.

Roger fought well-known boxers during his career like Julio Cesar Chavez, Vinny Pazienza, Pernell Whitaker and Kostya Tszyu.

After his boxing career, Roger became a trainer for his nephew, Floyd Jr., who is 50-0 and arguably the best boxer in history. Roger had some controversy as a trainer, such as when he entered the ring during Floyd Jr.’s fight with Zab Judah and fought with Zab’s father. He was later fined. He also was arrested in 2009 for attacking one of his former fighters.

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