Reliable sources have notified that undefeated light heavyweight Thiago Silva is no longer expected to fight Lyoto Machida at UFC 89 on October 18 due to a back injury.

The UFC has yet to confirm Silva’s departure from the card but an official announcement is believed to be forthcoming.

It is not known if the UFC was able to immediately secure a new opponent for Machida, as the promotion has had trouble in the past finding willing opponents.

The 25-year old Silva is a native of Sao Paulo, Brazil and is 13-0 in his professional mixed martial arts career, according to Sherdog’s fight finder. Since debuting in the UFC at UFC 71 in May of 2007, Silva is 4-0 in the Octagon with wins over James Irvin, Tomasz Drwal, Houston Alexander, and Antonio Mendes.

Machida is also undefeated with a record of 13-0 and is 5-0 in the UFC. His notable UFC wins have come against Kazuhiro Nakamura, Rameau Thierry Sokoudjou, and Tito Ortiz, who served as his most recent opponent in May at UFC 84. Outside of the UFC he holds notables victories over Rich Franklin, B.J. Penn, and Stephan Bonnar.

UFC 89 will emanate from the National Indoor Arena in Birmingham, England and will be televised on Spike TV on a tape delay basis in the United States. The featured bout on the card will be a middleweight matchup between Michael Bisping and Chris Leben. A light heavyweight fight between Brandon Vera and Keith Jardine is scheduled as well.

(Pictured: Thiago Silva)