Khabib Nurmagomedov has raised doubts over his scheduled fight with Tony Ferguson, revealing he does not even know where UFC 249 is going to take place.
The lightweight title bout was due to be staged in Brooklyn on April 18, but the coronavirus pandemic forced a rethink over the venue.
UFC has already been forced to postpone three events due to COVID-19, though president Dana White said at the time that Khabib against Ferguson was "still on".
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However, having reportedly returned to Russia, Khabib - the champion at the weight - put the fight in doubt on Monday with his comments in an Instagram post.
"We can't understand what is happening at all," he said, as translated from Russian.
"Where are we fighting and are we fighting at all? What about the weigh-in and the venue for the battle. UFC 249 what are you?"
The unbeaten Khabib was last in action in September, defeating Dustin Poirier in Abu Dhabi to retain his title and extend his winning streak to 28 fights.