UFC announced on Friday that top-ranked contender Urijah Faber has pulled out of his scheduled fight against Masanori Kanehara at UFC Fight Night 52.

Faber, who has yet to explain why he has pulled out of the fight, will be replaced by Alex Caceres at the show.

Caceres-Kanehara is scheduled for UFC Fight Night 52, which takes place on September 20th at the Saitama Super Arena in Saitama, Japan. The show is scheduled to air exclusively on UFC Fight Pass.