WBO super flyweight champion Naoya Inoue will have his scheduled first title defense in May postponed after injuring his right hand, his Ohashi Boxing Gym said Tuesday.

According to the gym, Inoue, 21, injured his right fist in his match against Argentina's Omar Narvaez, whom he knocked out in the second round to win a world title in a second weight class on Dec. 30, 2014 — achieving the feat in his eighth pro bout for the quickest pace by a Japanese boxer.

It was not made clear whether the hand is broken or not, and no date has been set for his next bout.