UFC 176’s headliner-less card already has done a significant amount of business at the box office, even if questions remain about the event’s pay-per-view viability.

A source close to the event on Monday told MMAjunkie that the Aug. 2 show at Staples Center in Los Angeles has generated $800,000 in revenue from ticket sales. The source spoke on condition of anonymity because he wasn’t publicly allowed to discuss the matter. UFC officials declined to comment on current sales for the event.

The number of tickets sold for the event wasn’t immediately available. UFC 176 was scheduled to be headlined by a featherweight title rematch between champ Jose Aldo and Chad Mendes, but Aldo was forced to withdraw due a neck and shoulder injury.

UFC President Dana White said this past Sunday that Aldo and Mendes will eventually fight, but Aldo’s recovery window puts UFC 176 out of reach. Asked about a replacement, White brushed off the question to deal with the issue later, saying he’d prefer to enjoy the aftermath of the two title fights at UFC 175, which took place Saturday in Las Vegas.

Although the dominant Aldo isn’t known as a big pay-per-view attraction in the UFC, the featherweight title fight added a prestige to the event that now appears to be lacking. The card’s co-headliner is a middleweight title fight between ex-Strikeforce champs Gegard Mousasi and Ronaldo Souza, who have never headlined a PPV event.

With less than a month’s notice to prepare for a five-round fight, the promotion faces a tough sell in convincing a headliner to step up, though women’s bantamweight champ Ronda Rousey volunteered for the job before White told her it wasn’t an option.

Previous UFC trips to Los Angeles have met with success at the box office, though revenue has declined. UFC 60 drew 14,802 fans (10,347 paid) to the Staples Center for a live gate just shy of $3 million. Three years later, UFC 104 drew 14,892 fans for a $1.9 million gate. Most recently, the promotion held UFC on FOX 4 at the arena and drew a reported 16,080 fans for a $1.1 million gate.

For the latest on UFC 176, stay tuned to the UFC Rumors section of the site.