The UFC’s return to Russia on April 20th will get a new main event after Alexander Volkov was replaced by Aleksei Oleinik.

As first reported by ESPN’s Ariel Helwani, Oleinik has been moved from his scheduled May 4th bout with Walt Harris into the main event at UFC: St. Petersburg against Alistair Overeem.

While Volkov has withdrawn from his five-round bout with Overeem for undisclosed reasons, Russian outlet MatchTV are reporting that Volkov has been flagged by the UFC’s drug testing partner USADA.

Oleinik (57-11-1) is currently on a two-fight winning streak in the heavyweight division and was last seen headlining the UFC’s debut show in Russia this past September. Oleinik would record a rear-naked choke against Mark Hunt at UFC: Moscow, the 45th submission win of his professional MMA career.

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Overeem (44-17, 1 NC) meanwhile snapped a two-fight losing streak in his most recent contest as he earned a first-round TKO over the then-unbeaten Sergei Pavlovich.

UFC: St. Petersburg is now currently scheduled to feature:

  • Alistair Overeem vs. Aleksei Oleinik
  • Islam Makhachev vs. Arman Tsarukyan
  • Sergei Pavlovich vs. Marcelo Golm
  • Ivan Shtyrkov vs. Devin Clark
  • Roxanne Modafferi vs. Antonina Shevchenko
  • Kryzystof Jotko vs. Alen Amedovski
  • Movsar Evloev vs. Seung Woo Choi
  • Sultan Aliev vs. Keita Nakamura
  • Alexander Yakovlev vs. Teemu Packalen
  • Marcin Tybura vs. Shamil Abdurakhimov
  • Gadzhimurad Antigulov vs. Michal Oleksiejczuk
  • Magomed Mustafaev vs. Rafael Fiziev