Nikki Bella Brie Bella
Nikki Bella and Brie Bella visit AOL Hq for Build on Sept. 28, 2016 in New York City. Noam Galai/AOL Build

With "Total Bellas" set to premiere on E! On Wednesday, Oct. 5, fans will get a behind-the-scenes look at some of the biggest names in WWE. The spin-off of "Total Divas" follows Nikki Bella, John Cena, Brie Bella and Daniel Bryan all living under the same roof, capturing the end of both Brie and Bryan's wrestling careers.

Bryan retired as an in-ring performer on Feb. 8 because of issues related to the various concussions that he suffered throughout his career. The "Total Bellas" cameras were rolling just as Bryan came to the realization that he wouldn't be able to make a comeback from his latest injury.

"We had no idea that Bryan would have to retire, and the cameras caught all that," Brie said Wednesday at AOL's BUILD series in New York City. "And it was a point where like, 'Do we just go? Do we stop the project and just go back to Phoenix?' And Bryan wanted to power through it. But you know in the six episodes you really see someone trying to be so strong and decline as the series goes on."

One of the most popular WWE superstars of the last decade, Bryan suffered his second serious injury in as many years when a concussion put him on the shelf in April 2015. Bryan continued to petition WWE to let him wrestle, but the company's doctors refused to clear him to compete in the ring. He eventually relented in February, announcing his retirement in an emotional segment on "Monday Night Raw."

Bryan continues to second-guess his decision, though he cites his plans to start a family with Brie as a reason for staying out of the ring. Hoping to have children soon, Brie was already preparing to call it quits when Bryan did so, and she had her final match at WrestleMania 32 on April 3.

"It was hard as a wife to see that, especially because I had two months left at WWE and I was trying so hard to enjoy the ending, but it was hard for me because of what he was going through and I didn't really want to retire," Brie continued. "It's kind of bittersweet for me because we want to be parents, and I can't take back bumps and have a baby bump."

Cena and Nikki were out of action during the filming of "Total Bellas," as well. Cena underwent shoulder surgery in January and returned on Memorial Day. Nikki had a neck injury that nearly ended her career, but she returned to the ring at WWE SummerSlam 2016 on Aug. 21, having her first match in 10 months.