Lesnar will be undergoing another bout with diverticulitis.
The last time Lesnar battled the disease he was out for a year.
Since joining the UFC in 2008, Lesnar has been the company's biggest draw.
Besides being a former WWE champ, Lesnar is known for his huge size, and memorable quotes.
Here are some of the former champ’s most famous quotes.
Although Brock only had one pro fight before entering the UFC, he was not given an easy first fight.
Taking on former champion Frank Mir, Lesnar dominated the fight until he got caught in a knee bar.
Lesnar’s second UFC fight played out much like the first one, only Lesnar dominated and beat Heath Hearing.
After the fight Lesnar yelled out to the crowd, “Can you see me now!”
This was Lesnar’s moment that showed he had arrived.
Following a year long layoff due to a battle with diverticulitis, Brock would make his return at UFC 116.
Shane Carwin was Lesnar biggest threat at the time due to his KO power.
Carwin had Lesnar hurt badly, and the fight could have been stopped at any moment in the first round.
Lesnar regained his composure and took advantage of Carwin being gassed out. Lesnar won the match by submission in the second round.
After the fight, Lesnar was very humble thanking friends, family, and trainers. Lesnar then stated, “I am blessed by God.”
Lesnar will need another blessing as he will have to undergo another bout with the diverticulitis.
Trash talk between Lesnar and Mir could be seen on the countdown to UFC 100.
Brock believed Mir had a Horseshoe stuck somewhere and he was going to help him remove it.
After Brock won the second fight, he gave his most infamous post-fight interview.
Of the memorable quotes, two that sick out was Brock saying he would go home and “drink a Coors Light,” and “I might even get on top of my wife.”
One of the UFC’s biggest sponsors is Coors Light rival Bud Light.
Brock later apologized for the comments.
The video above is from Brock's WWE days.
Fast forward to UFC 121.
Brock may not have had the mariachi band playing, but he did say something disrespectful about Cain's Mexican heritage.
In one of the interviews leading up to the fight Brock said, "When I get done whooping his ass, I’m gonna go drink a Corona and eat a burrito just for your Hispanic heritage.”
Brock would have to eat those words as he lost to Cain by TKO in the first round.
Brock Lesnar and Junior dos Santos have been two of the most respectful coaches on The Ultimate Fighter.
They have had little interaction with each other, and when they’re in the same room with Dana White, they’re usually agreeing on something.
Brock and his team members are another issue.
Although Brock has tried to encourage the team by saying they can turn nothing into something or “Chicken s*** into chicken salad,” some of the Team Lesnar members haven’t taken kindly to being called chicken s***.
The news that Brock will have to undergo a second battle with diverticulitis came as a shock.
After the first round with the disease, Brock changed his diet and tried to do everything right to avoid it happening again.
Now that it has come back, many are wondering if Brock will be able to fight again.
Brock remains opptimistic about the situation.
"I'll tell you one thing. I'm not retiring," Lesnar said.
"This isn't the end of my fight career. This is something that I believe that there is a solution to every problem. I just have to find the right solution to fix this problem."