"We were shooting this thing and we had a bit of a tumble on a bike and I landed pretty hard," Nick said of the on-set incident, which left him with a cracked rib. "It was brutal."
"Kevin also ran into you as well," Joe chimed in.
"Yeah, he did," Nick agreed, before looking over at his oldest brother.
"I may have also helped in the injury," Kevin admitted, before joking that they "haven't seen the footage yet."
"We're not so sure if Joe just didn't kick us on the side just to make sure," Kevin said.
Despite Kevin's potential involvement in his injury, Nick still turned to his oldest brother in the time of crisis.
"It was a test of a lot of things. Trust, I think, is the biggest thing," Nick said, before sharing how he decided to trust Kevin in that moment.
"Basically I was there and the medics were attending to me. I was about to put on the gurney to get in the ambulance. Obviously, I had to call Priyanka [Chopra], my wife, to say, 'This has happened,' but I wasn't really in a spot where I could talk to her because they were doing all the things they were doing," Nick explained. "So it was a choice between Joe and Kevin. Who [do] you give your phone to to call your wife in a time of crisis? I gave it to Kevin."
"It's kind of telling," the chosen brother responded, before revealing why he thinks Nick trusted him with the task.
"I was really calm and collected," Kevin said. "I think it has something to do with being a father and seeing children fall all the time."
"I love how he's equated my rib breaking and the whole thing to kids falling," Nick quipped of his brother, who's dad to Alena, 7, and Valentina, 4, with his wife, Danielle.
"Well, they fall on their bikes. It's a big deal in the moment, but it's like, if you get freaked out, then they get more freaked out, so I try to stay extremely calm," Kevin explained.
"I have the same emotional maturity as his 5-year-old," Nick joked in response.
As for how he's doing now, Nick said that he's "surprised at how good I feel."
"I'm feeling amazing," he said. "... Right after it happened I had to be OK because I was doing The Voice and a couple other things. It just somehow healed up pretty fast."
When ET's Kevin Frazier spoke to Nick following his injury, the singer opened up about the injury.
"Something just got caught, dirt on the bike, and [I] just tumbled," he said. "... A little spill. A fractured rib and some other bumps and bruises, but I'm feeling really lucky. It probably could've been a little worse. All is good. I'm recovering nicely."
"I've got a lot of support around me and I appreciate everyone's well wishes," he added. "It means a lot."
Watch the video below to see more of ET's interview with Nick.