A bantamweight bout between WEC star Urijah Faber (23-4) and Takeya Mizugaki (13-4-2) has been scratched from next month's WEC 50 card after Faber withdrew from the event due to an undisclosed injury suffered in training.

Faber revealed the news on his official Twitter account.

Been quit the last few days," said Faber in the post. "I was injured in pract on Mon. Just got results Im Out on Aug 18th."

The injury was reportedly suffered to Faber's lower body, however, the severity of his injury is not yet known and his timetable for his return is also currently unknown.

Mizugaki will reportedly be removed from the card altogether, as the WEC does not plan to seek out a replacement opponent for the Japanese fighter. Faber vs. Mizugaki was slated to serve as the night's co-main event and WEC officials are still trying to decide which bout will now take the event's co-headlining slot.

Faber was going to be making his bantamweight debut at the event after going 2-3 in his last five bouts as a featherweight. He recently suffered a unanimous decision loss to Jose Aldo in the main event of WEC 48 event in April, which was the promotion's first ever Pay-Per-View card.

Prior to the dismal stretch, Faber was ranked the number one featherweight in the world after putting together an impressive 13-fight winning streak from Oct. 2005 to June 2008, which included wins in his first six WEC bouts.

"The California Kid" has put together an 8-3 record during his long tenure with the WEC, capturing the promotion's featherweight title in March 2006 by defeating Cole Escovedo. He held on to the title for more then two years, which included five successful title defenses. Faber holds other notable WEC wins over current bantamweight champion Dominick Cruz, Chance Farrar, Jeff Curran, Raphael Assuncao and Jens Pulver (x2).

WEC 50 takes place on August 18 at The Pearl at the Palms Casino Resort in Las Vegas, Nevada and is headlined by a WEC bantamweight title bout between champion Dominick Cruz and Joseph Benavidez.

Update via MMAWeekly.com: 

"Faber's manager, Mike Roberts of MMA Inc has confirmed his removal from the WEC 50 card. According to Roberts, Faber suffered a a slight knee injury during training that will not require any kind of surgery, but will push his next fight back.

 Faber could return as early as the September 30 card currently rumored to take place in Colorado, but nothing has been confirmed as of yet."