Soulja Boy has Floyd Mayweather in his corner for the match against the rapper, but now Brown has “Iron Mike” 50 Cent has thrown his hat into the rapper feud ring by enlisting Iron Mike Tyson to train Brown in his upcoming boxing match against Soulja Boy. “They said Floyd [Mayweather] is training Soulja Boy, so I said I had to get Mike Tyson to train Chris Brown ,” FIf said on Instagram Friday night.