Set for December 11, a night before UFC 194 in Las Vegas, the card is expected to air on FOX Sports 1 with Edgar-Mendes serving as the main event.
Edgar, a former UFC lightweight champion and one-time featherweight title contender, has recently accepted challenges from Jeremy Stephens and Max Holloway. He is coming off a victory over Urijah Faber in May that pushed his win streak to four.
Overall, “The Answer” is 19-4-1 in his carer, including 10-3-1 in his last 14.
Mendes (17-3) lost in his pursuit of UFC gold in July when he was finished by Conor McGregor for the interim title. All three of his pro defeats have been in championship matches, as “Money” was bested twice by Jose Aldo.