In response to his departure from the organisation, Cena said at the time: “This is what happens when idiots have confidence.”
Now reflecting on the fallout, Cena said: “It’s all in good fun and it’s all for the business, but you’re supposed to have trust with each other and I violated his trust.
“It’s only when we started the build-up to New York that I got to look at myself in the mirror deeper and say I was wrong.
The 46-year-old remorsefully said he regretted airing his grievances with Johnson publicly instead of talking to him personally.
He told Josh Horowitz’s Happy Sad Confused podcast: “Instead of going like, ‘Hey man, I’d like to try to do this thing to hook you back in and maybe we can collaborate and really make it big.’
“I was just like, ‘Eff this, I’m calling this dude out. This is a moment. You gave me an opening. I’m going to kick the door in.’
“Not only did I hope that he would understand my perspective, but a year later I could admit that my perspective was wrong… We could’ve done it with everyone working together and playing nice and that was my fault.”
Now having perspective on the situation, Cena admitted he “understands why [Johnson] got upset” and explained that his actions caused “a lot of bad vibes between” them.
The Fast X star added: “I just got selfish and wanted a main event marquee match because it would better what I thought was the business. That was short-sighted and selfish. It worked!
“But it worked at the cost of two people who communicated and almost put it in jeopardy. There was a moment where there was a lot of bad vibes between us and rightfully so.”
The Sisters actor said that while he and The Rock made for great on-screen rivals, that came “at the cost of our friendship”, which he added “now is in a really good place”.
Johnson previously addressed the truth behind their rivalry during a recent appearance on The Late Show with Jimmy Fallon.
The 51-year-old shared: “We had a great rivalry. In the world of wrestling, it’s fictionalised, it’s a show, but here’s the thing. Our rivalry was, it was so real. We had real problems with each other.”