UFC's annual show during the weekend of July 4 will reportedly have two major bouts added to the card.
In addition, per MMA Fighting's Ariel Helwani, Francis Ngannou vs. Derrick Lewis in a heavyweight showdown has been scheduled for the show's undercard.
UFC previously announced that Stipe Miocic will defend the heavyweight championship against Daniel Cormier in the UFC 226 main event.
Holloway hasn't fought since defending the featherweight title against Jose Aldo on Dec. 2. He was scheduled to fight Frankie Edgar at UFC 222 in March but had to withdraw from the bout due to a leg injury.
UFC named Holloway as Tony Ferguson's replacement to challenge Khabib Nurmagomedov at UFC 223, but a failed weight cut left him unable to compete.
Ortega, who replaced Hollway at UFC 222, defeated Edgar via first-round knockout. The 27-year-old has a 14-0 record with one no-contest in 15 career fights.
Ngannou is coming off a unanimous-decision loss against Miocic in a heavyweight title fight at UFC 220. Lewis got back on track with a victory over Marcin Tybura in February. His last four matches have all ended via knockout or TKO.