Fans of the Creed and Rocky franchises may have noticed that Creed 3 was lacking an important legacy character in Ivan Drago. While the film already missed the presence of franchise creator Sly Stallone as Rocky, Dolph Lundgren's Ivan Drago was also notably absent. Creed 3 took a new direction for the franchise, featuring the original character, Damien Anderson (Jonathan Majors), as its central antagonist. Ivan's son, Viktor Drago (Florian Munteanu), who was the main antagonist of Creed 2, was also present in the film as a supporting character to Adonis "Donnie" Creed (Michael B. Jordan).

https://screenrant.com/why-ivan-drago-doesnt-return-creed-3/