Mayweather responds to Khabib Nurmagomedov's challenge

By Allan Fox: In response to being called out by UFC lightweight champion Khabib Nurmagomedov last Sunday, Floyd Mayweather Jr. took to social media to tell Showtime and the MGM Grand to get their checkbook out if they want to see him fight the 30-year-old MMA star in what presumably would be another novelty boxing match.