Former heavyweight champion Brock Lesnar will end his retirement from mixed martial arts on July 9 as he returns to action at UFC 200.

The announcement was made during UFC 199 on Saturday night.

Lesnar, who turns 39 next month, hasn't fought since 2011 when he fell by TKO to Alistair Overeem at UFC 141 and promptly announced his retirement from fighting afterward.

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Since that time, Lesnar has been part of the WWE, where he re-established himself as one of the biggest stars in professional wrestling.

Last March, Lesnar signed a new deal with WWE and said he was closing the door on his mixed martial arts career for good.

"It was a very hard decision for me. The fighter inside of me wants to compete. I'm an older caveman now, so I make wiser caveman decisions. So I'm here to say that my legacy in the Octagon is over," Lesnar said at the time.

OH. MY. GOD. 😳 #UFC200https://t.co/ffhsOYIRvz

— #UFC199 (@ufc) June 5, 2016

Last October, Lesnar spoke about his continued desire to fight again after his bout with diverticulitis took away years from his career and effectively forced the heavyweight to rethink his future while battling against his own body.

"I felt robbed by diverticulitis. I felt robbed by being sick. I was feeling good and it took me a couple years to start feeling good (again). I'm at home, I'm working out, my life is great, everything's in tune, my contract's coming to an end with WWE, hey it's been a great time but something's missing," Lesnar said.

"I was up front and totally honest with the company and told them I'm really thinking of pursuing getting back in the Octagon."

It appears his desire to fight again finally got the better of Lesnar because he's finally ready to return to the Octagon at UFC 200. Following the announcement, WWE released a statement about Lesnar's future with the promotion.

"Brock Lesnar remains under contract to WWE, however, he has been granted a one-off opportunity to compete at UFC 200," WWE officials said on Saturday. "Following this milestone event on July 9, Brock will return to WWE for SummerSlam Sunday, August 21, live on WWE Network."

No opponent was named for Lesnar when his return was confirmed, but UFC officials are expected to make an announcement in the coming days.

Lesnar will fight in the co-main event for UFC 200, which will be headlined by Daniel Cormier facing Jon Jones with the light heavyweight title up for grabs.