Marco Galán, a banderillero during one of the last bullfights of the Feria de San Isidro, suffered an "eviscerated testicle" after being gored in the groin.
He had just stabbed the bull with the two banderillas when the bull swiped him with his left horn. The bull then caught Galán through his sequined jacket with his left horn.
The grisly goring was caught on camera.
Warning: Graphic footage
Within seconds other bullfighters rushed to his rescue to distract the bull and Galán walked out of the ring, bleeding profusely.
Speaking from his hospital bed on Tuesday morning, he told The Local about the moment his scrotum was ripped open.
"My testicle was ripped open," he said from his room at the Hospital San Francisco de Asís in Madrid. "It wasn't a great moment for me."
Describing the moment it went wrong, he told The Local: "I placed the bandarillas well, but then it went a bit wrong and then I was on the horns of the bull."
But the bullfighter from Alcázar de San Juan near Ciudad Real in Castilla La Mancha is determined not to let a small thing like an "enviscerated testicle" put him off.
"It was over very quickly and I got away. These things happen when you go in the ring. But bad things can also happen just walking down the street."
He said he expected to be discharged around lunchtime.
"I am making a good recovery and I will back in the ring again soon. I have a bullfight in France on July 5th and should be OK by then.
"Thanks to God that I was spared. I feel very lucky. I love Las Ventas in Madrid, it's my favourite bullring," he said.
"But on Sunday it just didn't go my way."