UFC welterweight Thiago Alves (21-10 MMA, 13-7 UFC) has sustained a broken rib and is unable to fight Benson Henderson (22-5 MMA, 10-3 UFC) at UFC Fight Night 79, according to a source close to Alves and a UFC official.

The sources confirmed the news to MMAjunkie after Twitter user @TalkMMA first reported it. The sources spoke on the condition of anonymity because they weren’t authorized to publicly discuss the matter.

The UFC official told MMAjunkie a replacement search is underway for Henderson, who was due to headline the Nov. 28 event opposite the onetime UFC title challenger.

Henderson may have tipped his hand about the withdrawal. The UFC announced the fight in late August, but in early November, he wrote a cryptic tweet.

UFC Fight Night 79 takes place at Olympic Gymnastics Arena in Seoul, South Korea. The event streams live on UFC Fight Pass.

Alves’ injury pauses his career amid a comeback effort. A serious knee injury in 2012 benched him for two years. Since then, he’s gone 2-1, though a TKO setback to Carlos Condit in May sapped his momentum.

Henderson, meanwhile, is looking to build momentum in the 170-pound class, where he debuted in February with a short-notice win over Brandon Thatch at UFC Fight Night 60.

With the change, UFC Fight Night 79 now includes:

MAIN CARD (UFC Fight Pass, 8 a.m. ET)

Benson Henderson vs. opponent TBA Dong Hyun Kim vs. Jorge Masvidal Yoshihiro Akiyama vs. Alberto Mina Hyun Gyu Lim vs. Dominique Steele

PRELIMINARY CARD (UFC Fight Pass, 4:45 a.m. ET)

Doo Ho Choi vs. Sam Sicilia Jake Collier vs. Dongi Yang Yui Chul Nam vs. Mike De La Torre Tae Hyun Bang vs. Leo Kuntz Cortney Casey vs. Seo Hee Ham Fredy Serrano vs. Yao Zhikui Marco Beltran vs. Ning Guangyou

For more on UFC Fight Night 79, check out the UFC Rumors section of the site.