Has Conor McGregor's market appeal suffered a knock-out blow?
Guru warns punch-ups will hurt MMA star
Controversy: Conor McGregor reacts after losing to Khabib Nurmagomedov in his last UFC fight in Las Vegas in October 2018. Photo: AP
Ralph Riegel
One of the world's leading sports marketing experts has warned that Conor McGregor's latest controversy could herald the beginning of the end for the fighter's commercial appeal.