Rocky, who is now training Apollo Creed's son, is two years older than Mickey was when he trained Balboa in the original Rocky (1976).
Dolph Lundgren collaborated with director Steven Caple Jr. to change his physique and age the character of Drago to visually translate the poverty and suffering endured, as he colored in his teeth yellow.
Just like Rocky IV (1985), none of the prominent Russian characters are played by Russian actors. Dolph Lundgren is Swedish, Florian Munteanu is German-Romanian, and Brigitte Nielsen is Danish.
An important plot point in the film is Rocky's feelings of responsibility and guilt for not stopping the fight when Apollo Creed was killed in the ring by Ivan Drago in Rocky IV (1985). However, the writers chose to omit the fact that the referee attempted to stop the fight, but was thrown aside by Drago who continued to hit Creed, and ultimately killed him in the ring. So even if Rocky had thrown in the towel, it seems doubtful that Drago would have stopped fighting just because Rocky threw in the towel, since he already completely ignored the referee's attempt to stop the fight.