By Philip O'Connor
(Reuters) - The Ultimate Fighting Championship is gearing up for one of the biggest events in its history in Las Vegas on Saturday, but a high-profile doping case has cast a shadow over the celebration of the fast-growing sport of mixed martial arts.
UFC 200, which boasts one of the most stacked cards in the promotion's history, will cap days of events collectively dubbed International Fight Week that includes amateur championships, a fan expo and some of the sport's biggest names in action.
But the top-billed light heavyweight title fight between Daniel Cormier and Jon Jones was abruptly canceled this week after the United States Anti-Doping Agency informed UFC that the latter failed an out-of-competition dope test on June 16.
With the enormously popular Irish featherweight champion Conor McGregor previously kicked off the bill for not fulfilling promotional commitments, Jones was set to meet Cormier in a much-anticipated main event.
With Jones, who was stripped of the light heavyweight belt in April 2015 after he was involved in a hit-and-run accident, now out pending the result of tests on his B sample, Cormier loses top billing but will still fight on Saturday.
The UFC found a replacement at just two days' notice in Brazilian former middleweight champion Anderson Silva, who has previously served a suspension for a doping violation.
The title fight between holder Miesha Tate and Amanda Nunes in a hugely competitive women's bantamweight division that also includes previous champions Ronda Rousey and Holly Holm is now the main event.
Last-minute changes to high-profile fight cards are nothing new in the UFC and even if they can have a negative affect on pay-per-view sales, they have done little to slow its growth around the globe.
"Over the past couple of years, within the EMEA market specifically, there has been a greater public awareness and support for the sport and a rise in demand for UFC product and content," James Elliott, UFC Vice President and General of Europe, Middle East and Africa, told Reuters.
Bought for $2 million by the Fertitta brothers Lorenzo and Frank in 2001, the company that controls the UFC, Zuffa LLC, is rumored to be exploring a sale that could value that promotion company at $3.5 billion to $4 billion.
With the enormously popular McGregor set for a rematch against Nate Diaz, who shocked the fighting world in March when he defeated the Irishman, and Rousey also set to return, the UFC looks set to continue to grow in popularity.
But a little over a year into its anti-doping co-operation with USADA, the organization is still coming to grips with performance-enhancing substances, as evidenced by Diaz's comments about the Jones test at a news conference on Thursday.
"Everybody's on steroids," he joked.
(Reporting by Philip O'Connor in Stockholm; Editing by Frank Pingue)