Just a little more than one week before the UFC’s return to the Philippines, the event has lost its headliner.

MMAjunkie today confirmed with a person with knowledge of the booking that B.J. Penn (16-10-2 MMA, 12-9-2 UFC) has suffered an injury in training and has been forced out of a planned matchup with Ricardo Lamas (16-5 MMA, 7-3 UFC) in the main event of UFC Fight Night 97. That person was not allowed to speak publicly because the withdrawal has not been formally announced.

It’s currently unclear if the UFC will be able to replace Penn in time for the event.

UFC Fight Night 97 takes place Oct. 15 at SM Mall of Asia Arena in Pasay, Manila, Philippines. The entire event streams on UFC Fight Pass.

Penn, who’s previously held the lightweight and welterweight titles, had looked to fight for the first time since his July 2014 loss to Frankie Edgar, which marked a third straight defeat and prompted a retirement announcement. The 37-year-old “Prodigy” ultimately decided to return to competition (with planned bouts against Dennis Siver and then Cole Miller), but it’s been slowed by a six-month USADA suspension due to his disclosure of banned IV use, as well as a legal issue. The Hawaiian and jiu-jitsu ace now jumps back into a headlining spot.

He was expected to meet Lamas, a former title challenger who’s No. 6 in the USA TODAY Sports/MMAjunkie MMA featherweight rankings. The 34-year-old WEC vet was on a 3-1 run, which included victories over Diego Sanchez and Dennis Bermudez, before a recent unanimous-decision loss to surging contender Max Holloway that resulted in a nasty split shin. His only other UFC losses have come to then-champ Jose Aldo and perennial contender Chad Mendes.

With the change to the lineup, UFC Fight Night 97 now includes:

MAIN CARD (UFC Fight Pass, 10 a.m. ET)

Ricardo Lamas vs. opponent TBA

Derrick Lewis vs. Marcin Tybura

Jenel Lausa vs. Yao Zhikui

Mizuto Hirota vs. Cole Miller

PRELIMINARY CARD (UFC Fight Pass, 6:45 a.m. ET)

Sam Alvey vs. Alex Nicholson

Jon Tuck vs. Alex Volkanovski

Ryan Janes vs. Dongi Yang

Seo Hee Ham vs. Danielle Taylor

James Moontasri vs. Alex Morono

Ali Bagautinov vs. Kyoji Horiguchi

For more on UFC Fight Night 97, check out the UFC Rumors section of the site.