Keenan Cornelius was supposed to return to competition on June 19, matching up against Haisam Rida at Who’s Number One (WNO). However, he had to withdraw from the match due to a back injury.
On a new episode of his Matburn Podcast, Cornelius explained how this injury happened.

May 2020, I was deadlifting and I was getting, kind of, I was feeling strong. I had been deadlifting for a few years, and I tried to set a new PR, which is just dumb… It was just an ego thing, and I felt like I was getting stronger and stronger.
I lifted too much weight. I repped to, like, 400 (lbs) or something for ten reps, and I was like ‘wow, I’m doing this so easy, I’m so strong.’

So I walked away and then my back just started feeling a little weird… I was just walking it off and about 15 minutes later, I couldn’t move. I was on the gym couch just unable to move.
Holy sh*st I really injured myself… For like three weeks I was bed ridden. I couldn’t stand. I couldn’t sit. I thought I had really damaged my body.

Cornelius received cortisone injections to help with pain. However, no matter how much those injections helped him with pain, his muscles have been injured still.
He kept upping his training intensity gradually, but as he was entering the final preparations for WNO, the injury flared up again.

During the training camp for the match against Haisam, I was ramping up, I was still being careful. It wasn’t another acute injury. I was making sure that I could push 100% without injuring myself. I had been holding back in the training a little bit…
The last two weeks before the camp ended, I really was pushing hard, like I hadn’t pushed in over a year, and I was really feeling good and ready to go, and then bam. I just walked off the mat and it was the same feeling. [My back] started to seize up again, and I just can’t risk this, I can’t be out again. I have to protect this, I have to just take it easy, I have plenty of years left.”

Keenan’s black belt, Miha Perhavec, jumped in for Cornelius at WNO and lost by submission.