Ginjiro Shigeoka, the never-say-die Japanese fighter who lost to Filipino world champion Pedro Taduran over the weekend, is currently under observation in a private hospital in Osaka.

Viva Promotions reported on Tuesday that Shigeoka, who dropped a 12-round split decision in his bid to dethrone Taduran as International Boxing Federation minimumweight king, “suffered from an acute subdural hematoma.”

He underwent a craniotomy and the Japan Boxing Commission (JBC) has ruled that the 25-year-old former world champion should retire from the sport.

The JBC said that the next few days will be crucial in determining Shigeoka’s prognosis.

Shigeoka was rushed to a nearby hospital moments after the official announcement was made after collapsing.

He had to be stretchered out of the ring by his handlers and medical personnel.

It was Shigeoka’s second straight trip to the hospital following a fight.

In July last year, Shigeoka was also rushed to the hospital after losing the IBF 105-pound title on a ninth-round stoppage to Taduran in Otsu City.

Taduran, who arrived in manila last Sunday, expressed sadness over Shigeoka’s hospitalization but made it clear that it was all part of the sport’s risks.

“I feel bad for him but that’s part of the game. All boxers know about the risks and aware of what could happen to them, including this one,” Taduran said.