The "Creed" sequel is sticking close to its Rocky series roots.

Sylvester Stallone has been using social media to tease a tie-in between "Rocky IV" and the upcoming "Creed 2." Since late June, he has shared a flurry of photos featuring Ivan Drago (Dolph Lundgren), the Russian boxer who killed Apollo Creed in the 1985 film. Stallone seems to be hinting at the character's return in the spin-off series, which would make sense given their history.

In the latest image, posted July 2, Drago's head is Photoshopped into a picture, putting him face-to-face with "Creed" protagonist Donnie (Michael B. Jordan), the young man whose father he killed in "Rocky IV."

"Here's a chance to stretch your imagination," Stallone captioned the photo. "HISTORY WILL ALWAYS REPEAT ITSELF IN ONE FORM OR ANOTHER, JUST GOT TO BE READY! ... Sins of the Father..."

While we still haven't gotten any official confirmation of Drago's return, the idea is an intriguing one. A matchup in the ring might be strange considering that most boxers would be retired by Drago's age now, but maybe he has another fight in him. Lundgren has kept in shape, as we can see in the 2016 Instagram video below.

Fun in the makeup trailer!

A post shared by Dolph Lundgren (@dolphlundgren) on

We're sure they can find a way to work the Rocky villain into the story somehow.

See more of Stallone's recent Drago-centric Instagram posts below.

Directing APOLLO AND DRAGO , The two best "cinema "boxers that ever lived!... Maybe it's time to try to again?

A post shared by Sly Stallone (@officialslystallone) on

Sparring with heavyweight Giants can be a little tiring, but great fun.#CREED2

A post shared by Sly Stallone (@officialslystallone) on

Really like this RARE picture... ROCKY making DRAGO'S life difficult between takes!!! #CREED 2 #MGM @dolphlundgren

A post shared by Sly Stallone (@officialslystallone) on

[via: Sylvester Stallone/Instagram; h/t: EW]