Bader (27-5, 1 NC), who also holds the Bellator heavyweight belt, has been light heavyweight champion since 2017 but hasn't defended the title since that year after moving up to heavyweight. He won the heavyweight title by knocking out Fedor Emelianenko in the first round at Bellator 214 in January 2019.
In his last fight, Bader made his first defense of the heavyweight title in September against Cheick Kongo. That fight ended in a no-contest when Kongo could not continue after being poked in the eye.
Bader, who has won eight straight fights, is one of only two fighters in Bellator history to hold titles in two divisions at once. The other is current lightweight and featherweight champion Patricio Freire.
Nemkov (11-2) has won six straight.