Joshua beat Wladimir Klitschko at London's Wembley Stadium in April to add the WBA belt to his IBF title. Pulev is the mandatory challenger for Joshua's IBF belt and will fight for it in Cardiff, Wales.
"October 28 can't come soon enough. I have been eager to get back in the ring since Wembley and now we are confirmed and ready,'' Joshua said on Tuesday.
"I'll be locked away focusing on fight No. 20 for the next eight weeks. I am excited to experience the atmosphere in a sold out Principality Stadium and aim to give the fans a spectacular night,'' Joshua said.
