NASCAR Cup Series star Kyle Busch has revealed he once suffered a serious injury, but kept it secret from everybody.

Busch is no stranger to injuries, having missed the first 11 races of the Cup Series season in 2015 after breaking his leg in the Xfinity Series race at Daytona that year.

However, appearing on his wife Samantha's Certified Oversharer podcast, the 40-year-old has now shared the fact that he once broke a rib, but did not attend the hospital for it because then he would have had to declare it to NASCAR.

NASCAR RESULTS TODAY: Live Cup Series at Las Vegas coverage including stage winners and points

Kyle Busch's secret wreck injury

The conversation on the podcast began with Samantha stating: [Greg] Biffle has this idea, weren't they running like hooptie cars essentially?"

Kyle then told the story, explaining: "Essentially, it was like the Crown Vic division, but it wasn’t Crown Vics, it was the run what you brung. And we brought our helmets from the sand dunes, so I think we had our motorcycle helmets from riding our four-wheelers, with the goggles. And then the only belt you had was just the regular car seat belt. That's all we had.

"Somebody had a brilliant idea that we were going to run it backwards, we weren't even running it left-hand turns, we ended up running right-hand turns."

Busch continued, explaining how the wreck and subsequent injury came about.

"The leaders were coming up behind me, I was running low, trying to stay out of the way, like 'Go around me', they're not having the 'no we're not going to go around you, we're going to go beneath you' thing.

"They slam into me, and they're moving me up the track, now the thing finally starts to spin out, and so I'm cranking it to the right, and as it catches it hooks, and it turns dead left, and drives straight to that exit hole and I wail the exit hole, like come to a dead stop.

"I didn't just blow this guy's car up, I literally just destroyed it, like wrecked the crap out of it."

Busch didn't go to hospital

Samantha then revealed that Kyle only mentioned the injury on a plane 45 minutes later, with the latter also revealing why he didn't go to the hospital.

"It wasn’t until we were on the airplane for 45 minutes that you said, 'I think something's broken', and I was like, 'What?'"

"Yeah, I couldn't take deep breaths," Kyle added. "You don't go to the hospital because then you've got to report it to NASCAR, so you just go through the pain.

"So I'm at Fontana, we're running around there in practice and I'm like, 'my right side does not feel good, I have a broken rib.'

"Never said nothing, nobody ever knew, here we are telling it today."

READ MORE: NASCAR hits multiple Cup teams with penalties at Las Vegas including Team Penske