The UFC’s next trip to Sao Paulo is down one fight.

Boston Salmon has been forced to withdraw from his bantamweight bout opposite Brazil’s Raoni Barcelos at UFC Fight Night 119 on Oct. 28 in Sao Paulo, Brazil due to a left knee injury. The news was confirmed to MMA Fighting’s Guilherme Cruz following a report by Combate.

According to Barcelos’s team, the UFC will not be seeking a new opponent for him. The card will proceed with 13 scheduled bouts.

Salmon told MMA Fighting that he expects to require surgery, though a decision will be made after seeing a physician next Tuesday.

The 26-year-old Salmon was originally scheduled to fight Augusto Mendes at UFC Sao Paulo, but Mendes bowed out with an injury and was replaced by Barcelos. “Boom Boom” was signed by the UFC after defeating Ricky Turcios by unanimous decision in Week 1 of Dana White’s Tuesday Night Contender Series and earning a multi-fight contract.

UFC Sao Paulo takes place at the Ibirapuera Gymnasium and it will be headlined by a middleweight bout between Lyoto Machida and Derek Brunson.