Conor McGregor is undoubtedly one of the very best fighters in mixed martial arts (MMA) today. But even beyond his natural skill set, the Irishman is as tough as they come.
Leading into his UFC 189 showdown with then Ultimate Fighting Championship (UFC) Featherweight titleholder Jose Aldo, McGregor hinted that he was fighting through injury. Aldo would later pull out of the title fight, Chad Mendes would replace him, and McGregor would go on to defeat "Money" via second-round TKO to win the interim strap.
Still, the MMA world has always been curious as to how injured McGregor truly was.