Andy Ruiz Jr has vowed he 'will be a champion again' after losing his world heavyweight titles to Anthony Joshua last week.
The Mexican was beaten by the British fighter on a unanimous points decision after a cagey rematch between the pair in Saudi Arabia.
With other challenges ahead for Joshua, it remains to be seen where Ruiz will go next but he has promised to return to the top of the heavyweight division sooner rather than later.
In a tweet posted on Thursday night, Ruiz said: 'I’ll be back stronger. I WILL be a champion once again.
'I appreciate all the love and support from my true fans. I appreciate the haters as well and can’t wait to prove the haters wrong once again.
'Back to the gym. Let’s start this journey to the belts.'
Joshua was officially ordered by the World Boxing Organisation to defend his WBO title against mandatory challenger Oleksandr Usyk on Thursday night.
The WBO confirmed: 'The WBO World Championship Committee hereby orders the parties herein commencement of negotiations for the above-mentioned WBO heavyweight mandatory championship contest.
'Please be advised that the parties have 30 days upon receipt of this letter to reach an agreement.
'If an accord is not reached within the time frame set forth herein, a purse bid will be ordered pursuant with the WBO regulations of world championship contests.'
That means that Joshua will now have to face the prospect of defending his WBO title before June 4th.
If he does not agree to meet the Ukrainian former cruiserweight king before January 10, he will be forced to vacate his belt, dealing a setback to his hopes of adding the WBC crown.