According to a report from Combate, and a second report from MMA Fighting that also cites sources, dos Santos and Miocic are going to fight on May 13th. The bout will be part of UFC 211, which will take place in Dallas, Texas.
JDS and Miocic fought back in December, 2014, and the latter lost the very competitive fight via unanimous decision. Since then the Cleveland fighter has won four in a row, most recently, he took out Alistair Overeem in September to retain the heavyweight crown.
Dos Santos was stopped by Overeem, after he faced Miocic, but last April he defeated Ben Rothwell by UD.
The UFC hasn’t officially announced the fight, but a confirmation is reportedly expected soon.