Unified flyweight world titleholder Juan Francisco Estrada, who has not fought since September 2015, mainly because of a severe hand injury, vacated one of his belts on Wednesday.

According to the WBA, Estrada sent the organization a letter via his promoter, Zanfer Promotions, notifying it of his decision. He has not yet formally renounced his WBO version of the flyweight title, though he probably will and then move up in weight when he is ready to return to the ring.

"There is no reason expressed (in the letter) other than he needs time to decide his future in the sport," WBA president Gilberto Mendoza Jr. told ESPN.com. "He appreciated the relationship with our association and also said at the time he is ready he will come back to us."

Estrada (33-2, 24 KOs), 26, of Mexico, lost a highly competitive action-packed decision to Roman "Chocolatito" Gonzalez challenging him for a junior flyweight title in a 2012 fight of the year contender. In his next fight, Estrada moved up to flyweight and earned a split decision against Brian Viloria to claim two flyweight belts.

Estrada made five successful defenses of the unified title, beating quality opponents such as former world titleholders Giovani Segura and Hernan "Tyson" Marquez as well as Milan Melindo. In his most recent fight, Estrada knocked out Marquez in the 10th round.

There has been talk of a possible rematch between Estrada and Gonzalez (46-0, 38 KOs), who went on to win titles at flyweight and junior bantamweight (this past Saturday night) to go along with his wide recognition as the pound-for-pound king.