Cleveland Browns star David Njoku burned nearly a quarter of his body during his serious bonfire mishap earlier this season ... with the tight end's doctor revealing his injuries were "probably the most painful burn you can have."
The 27-year-old sat in front of a camera and detailed the September 29 incident this week ... giving a play-by-play of exactly what happened that fateful night.
Njoku said he likes to have bonfires in his backyard to relax on Fridays ... and after running out of his usual lighter fluid, he tried out a spray to ignite the logs in his pit.
Unfortunately ... when he went to start the fire, particles in the air caught ablaze and blew up in his face.
Dr. Joseph Khouri of University Hospitals explained the extent of Njoku's ailments ... saying he had second-degree partial-thickness burns, which involve the top two layers of the skin.
Khouri recommended Njoku not play right after the incident ... but of course, the tight end did the exact opposite -- suiting up for the Browns just two days later, calling the matchup against the hated rival Ravens "personal," and stating there was no way he wasn't going to play.
Njoku ended up recording six catches for 46 yards in the contest ... and he said he felt "intense" pain throughout.
Now, Njoku is using his platform to speak out on burn victim advocacy ... and is repping the American Burn Association for the league's "My Cause My Cleats" promotion this weekend.