Former UFC heavyweight champ Brock Lesnar is back fighting a serious illness and has pulled out of UFC 131 in Vancouver.
In a hastily called media conference, UFC president Dana White announced the former pro wrestler's ongoing battle with diverticulitis -- a serious intestinal disorder -- has forced him to withdraw from his title contender fight with Junior dos Santos scheduled for June 11. Shane Carwin will instead take Lesnar's place.
Lesnar was first struck with the illness two years ago while visiting Manitoba on a hunting trip and spent over a month in hospital as a result.
Lesnar says he has been dealing with great discomfort since being cleared to fight a few months after the original ordeal but says the heightened symptoms in the past weeks have rendered him unable to train for his upcoming fight.
"I wanted more than anything to fight Junior dos Santos and get a shot at (title holder) Cain Velasquez," said Lesnar.
"Right now, my health and my family are more important. There isn't a fight in the world that is worth my health."
The current coach of The Ultimate Fighter 13 is now grappling with the decision to continue to treat the pain with antibiotics and suffer through flare ups or have surgery -- which would put him out of commission longer.
He made it clear he was not calling an end to his career and he believes there are plenty of Octagon fights left in his future.
"I'm not retiring," said the 33-year-old.
"This isn't the end of my fighting career. There's a solution to every problem. I have to find the right solution for this problem."
Later, when asked if the severity of the disease and the lingering effects of colon surgery could indeed spell the end of fighting, the Minnesota native sounded less sure saying: "I hope not."
He said he is now turning his full focus on fighting for his health.
"I went down to the Mayo clinic and spent 14 hours meeting with doctors," he said.
"This is an illness that a lot of people have. But I'm not like a lot of people. I consider myself an elite athlete. There is tremendous strain on my body during training. So I was simply unable to get into the shape I need to be in to fight."
Diverticulitis involves the formation of pouches on the outside of the colon and causes severe abdominal pain, fever and nausea.
Lesnar changed his diet and other parts of his regimen when he was first diagnosed, but has been fighting with more severe flare ups in recent weeks.
"I've been able to manage it for the past two years but with the recent abdominal pain, I don't have the recovery," said Lesnar -- who apologized to dos Santos and to fans.
"My entire immune system is fighting this thing and it just runs me down."
Lesnar -- who is 5-2 in his MMA career -- lost his heavyweight belt to Cain Velasquez at UFC 121.
He has coached against dos Santos in The Ultimate Fighter this season and the two were to square off in Vancouver with the winner getting a shot at Velasquez and the title.
White says the promotion is fully behind Lesnar and his hopeful return to the Octagon but added: "He has some serious choices to make."