Nurmagomedov, 28, was forced to pull out of the highly anticipated fight the day before it was scheduled, after he was hospitalized because of medical complications during his weight cut. Ferguson was also pulled from the Las Vegas event as a result.
"Whoever you are or whatever you do, you'll get only what God prescribed for you," Nurmagomedov wrote on Instagram. "AlhamduliLlah for everything God gifted me for my 28 years, I got much more than I asked. I know that many people was waiting for this fight and I fail them.
"Want to bring my apologies for all my fans, UFC and my opponent Tony. My health is fine now, thanks God. These tough testing only makes me stronger."
Nurmagomedov (24-0), of Dagestan, was scheduled to make a disclosed fight purse of $500,000 for the five-round interim fight. The winner would have been in a strong position to challenge current lightweight champion Conor McGregor.
Nurmagomedov was taken to the hospital early Friday morning after experiencing pain in his liver. UFC president Dana White criticized Nurmagomedov's camp for going directly to a hospital without consulting the UFC first.
"If he would have called [UFC's] Dr. Davidson and Brianna, the two who handle all of the medical stuff for the UFC, they would have brought him right to the hospital," White said. "Apparently, he was treated horribly at Sunrise Hospital. Here in Vegas, that's no shock. He should have gone to Valley Hospital. [Doctor Davidson] would have got him right in and checked his vitals.
"I'm not saying the fight could have been saved, but maybe it could have."
White has not yet stated if he intends to book the interim title fight again. The promotion has attempted to book a matchup between Nurmagomedov and Ferguson (22-3) three times, all of which have fallen through. Nurmagomedov would need to fight prior to his observance of Ramadan, which occurs from May 26 to June 25 in 2017.