David Harbour Teases AVENGERS: DOOMSDAY Will Shake Up Alexei and Yelena’s Relationship

Alexei Shostakov and Yelena Belova have somehow become one of the most entertaining and strangely heartfelt pairings in the MCU, but David Harbour is warning Marvel fans that their relationship could be in for some trouble when Avengers: Doomsday arrives.

Harbour recently offered a small but intriguing tease about Red Guardian’s role in the upcoming Marvel movie, revealing that whatever goes down in Doomsday will directly affect Alexei’s relationship with Yelena.

He isn’t giving away exactly what happens, but considering how close the two became in Thunderbolts, it sounds like Marvel is going to put that bond through another major test.

While promoting his new series DTF St. Louis, Harbour was asked by Deadline what he could reveal about Avengers: Doomsday. Instead of getting into the massive superhero chaos waiting for everyone, he focused on something much more personal.

“You know that Yelena Belova [Florence Pugh] and Red Guardian have a connection. If you saw Thunderbolts*, you know how much they love each other and how much they’re trying to help each other. And Doomsday will affect that relationship.”

That could mean a whole lot of things, and Harbour understandably didn’t explain exactly how Doomsday changes their dynamic. Still, it’s an interesting clue about where Red Guardian’s story is headed after Thunderbolts*.

Alexei and Yelena’s relationship has always been messy, funny, frustrating, and genuinely loving. Alexei certainly isn’t winning any Father of the Year awards, but Thunderbolts gave the characters room to reconnect and showed just how important they are to each other. Knowing Doomsday is going to mess with that makes their involvement in the movie a lot more interesting.

Harbour has also teased that the New Avengers won’t exactly see eye-to-eye with the MCU’s original heroes. Speaking at San Diego Comic-Con 2026, Harbour talked about how the two Avengers groups approach superhero business very differently.

“I mean, there’s trouble for sure. We definitely approach things differently than those guys, and we have different ideas about how to do things.”

So, Alexei apparently has more than one problem coming his way. The New Avengers are going to clash with the old guard, while something happening during the larger Doomsday conflict threatens to change his relationship with Yelena.

That personal element could give Red Guardian and Yelena something meaningful to deal with amid all the multiversal insanity expected from the movie. I think it could be the whole leadership dynamic in the New Avengers, with Yelena leading the team.

Big Marvel event films can throw an absurd number of superheroes onto the screen, but the character relationships are usually what give all that spectacle some weight. Alexei and Yelena already have a fun and complicated history to work with.

Avengers: Doomsday is directed by Anthony Russo and Joe Russo, and with Red Guardian and Yelena caught up in whatever massive disaster is headed toward the MCU, it’ll be interesting to see what exactly Harbour is teasing.

Hopefully Alexei and Yelena make it through the experience with their wonderfully dysfunctional relationship intact.

Avengers: Doomsday hits theaters December 18, 2026.