MMA fighter Cris Lencioni was rushed to hospital after suffering a cardiac arrest during training.
The 28-year-old collapsed in a horror incident on June 8, his wife confirmed late Monday night.
Lencioni was preparing to fight Ireland's James Gallagher at Bellator 298 next month.
But the Portland, Oregon-born star was described as being in "uncharted territory" by his wife Marca after the accident.
She posted a picture of the MMA fighter and "little Cris" while writing on his Instagram page.
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Marca wrote: "The athletes at the gym were great and immediately called 911 and did their best to address his needs until paramedics arrived.
"We are currently in another state. He has been under the care of excellent doctors with I and much of his family by his side.
"We are currently in uncharted territory and taking everything day by day. Thank you for the continued support during this time."
His mother-in-law set up a GoFundMe page and detailed what happened during the incident.
The page read: "As you can imagine this was completely unexpected considering he is only 28 and in peak physical condition.
"Cris is currently in the ICU in his biggest fight yet.
"We believe in the goodness of God, and we don’t know anyone with more will, strength, and determination than Cris.
"Cris has already overcome so much in his life, and we have faith in his ability to overcome any obstacle."
Lencioni has fought 14 times in MMA and has been with Bellator since 2017.
He has won 11 of his pro bouts including his last one against Blake Smith on April 21.
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The 28-year-old's next bout was due to be on Aug 11 at Bellator 298 in Sioux Falls, South Dakota.
MMA promoters Bellator said: "We are aware of Lencioni's current medical condition and are monitoring the situation closely."
