| Last updated
Chimaev, 26, appeared to announce his retirement from the sport just three weeks after being forced to withdraw from his main-event bout against Leon Edwards.
The Russian-born Swedish fighter has been suffering from the long-term effects of COVID-19.
On Instagram, he wrote: "Thank you all so much for supporting me in my journey in this sport. I think I'm done,"
He added that while he didn't win a UFC title: "It's not the most important victory in this life.
"It may upset you, but my heart and body tell me everything."
Chimaev took to social media again to post a picture that showed a spray of what appeared to be blood in a sink.
He wrote: "The main thing is I do not know what this disease is but it is not easily outlived."
However, White insists that Chimaev is NOT retiring despite his statement on social media.
The UFC president says the promising welterweight - who has also fought middleweight - had an emotional training session, but isn't ready to quit.
"When he got here, the doctors took care of him, and they put him on prednisone, which is a nasty f**king steroid," he said.
"So, he's on prednisone, and he's supposed to be taking this thing and chilling, relaxing, and letting himself recover. He went in and f**king trained today, felt like sh*t, and got super emotional and posted that.
"He's not supposed to be training, but you know, this guy's a savage. He wants to fight like every f**king weekend, and now he can't even train, so he just got emotional and posted that, but he ain't quitting."
'Borz' (9-0) hasn't fought since September when he obliterated Gerald Meerschaert in 17-seconds at UFC Fight Night.
He's 3-0 inside the famed Octagon after bursting onto the scene on Fight Island last summer.
Chosen for YouChosen for You
Most Read StoriesMost Read