Worst BJJ injury...
I was asked by Prof. Caique to show the other BJJ students what a trained boxer can do to grapplers as they come in to clinch. I'd get off 4 to six strikes, the guys quickly learn that it was no joke, and that it hurts. So they would bull rush me and take me down.
I had the whole class 30 to 40 students go through this twice, no breaks, my legs were mush.
After that was over, I rejoined the class and we proceeded to grapple. The drill was simple, push the knee down, slide the knee to pass the guard. I was so tired, I thought cool... Go ahead pass, I let the guy I was training with know that I was beat and that I was sorry I wouldn't offer much resistance.
He grabbed my knee, he pushed it down, and something popped. It wasn't a ligament, as it was in the inside of my left thigh. That was a SCARY moment. The next day, the whole inside of my thigh had turned BLACK. By this time it hurt like hell, and I had to take a leave of absence.
I never did have it checked out. The "hemorrhaging" eventually faded. My legs are fine now.