With the two biggest Ultimate Fighting Championship (UFC) stars -- Ronda Rousey and Conor McGregor -- hinting that big changes are on the horizon, including whiffs of potential retirement, the world's leading mixed martial arts (MMA) league could find itself superstar-less to start 2017.
McGregor competes in less than two weeks, taking on Lightweight champion Eddie Alvarez in the main event of UFC 205, while Rousey returns after more than a year in self-imposed hibernation to try and win back her women's Bantamweight belt against division champion Amanda Nunes at UFC 207 on Dec.