D23 2019 brought a lot of surprises. Not only did we find out that we would be getting some brand new Disney Plus MCU series, there were also a few shocking casting announcements that very few could have predicted. While there are some high profile cases such as Kit Harrington starring as the Black Knight, or Gemma Chang returning to a completely different Marvel role, a couple of other casting choices flew under the radar.

RELATED: Disney+: 10 Things You Should Know About Ms. Marvel

The return of both Darcy Lewis and Jimmy Woo to WandaVision shows that Marvel is willing to dive deep into their list of supporting characters, in order to keep fleshing out the universe they have created. With the unexpected return of these characters, we're taking a look at some supporting characters that could return in a much bigger way during the next few phases of the Marvel Cinematic Universe.

LADY SIF

It's no secret that Lady Sif certainly has her fans. The Asgardian warrior has been absent from recent films after a scheduling conflict meant that she could not appear alongside the Warriors Three in Thor: RagnarokThis was probably good news for the adventurer however, as her brethren were killed in combat fighting against Hela. Sif was said to have perished during the snap, but will of course be around once again.

There's plenty of potential for Sif to now return, perhaps in the Loki series or Thor: Love and ThunderFans have been speculating that Sif could in fact be the Queen that Valkyrie has been searching for, marking a triumphant return to the franchise.

HARLEY KEENER

Avengers: Endgame saw the surprising return of another supporting character that had a much larger role during Shane Black's Iron Man 3The young inventor Harley Keener was briefly seen during the funeral of Tony Stark. The producers over at Marvel Studios clearly felt it was important to continue to show the connection between the two characters.

Harley may be in for a much larger role in the MCU. With a successor to Iron Man probably inbound, it makes sense that Harley is part of that journey. The Young Avengers are supposedly coming, with the addition of Kate Bishop and Cassie Lang to the MCU, so it's possible Harley joins them as their in house inventor and mechanic.

ARNIM ZOLA

Zola

Zola had a completely hidden cameo in Endgame thanks to the production crew behind the visual effects in the film. This recent reveal has only reminded fans just how good the character is though. We last saw Zola in his computer form in Captain America: The Winter Soldier.

RELATED: Disney+: 10 Things You Should Know About She-Hulk Before the Premiere

Zola has actually appeared in many more MCU properties than people might realise over the years and he is set to voice the animated version of the character for Disney Plus. However, with The Falcon and the Winter Soldier clearly bringing back many other supporting characters, it wouldn't be too much of a stretch to see Zemo written back into the universe.Someone so obsessed with surviving probably has a backup stored somewhere!

RICHARD MADISON

A random choice, perhaps, and maybe one that readers don't even remember! During Thor: The Dark World, Jane Foster starts looking for other romantic partners and goes on a date with Richard, portrayed by the fantastic Chris O'Dowd. It would certainly be brilliant to see Richard return due to the charismatic actor behind the character, but what larger role could Richard actually play in such a vast universe?

It's been a while since we've seen Jane Foster and there's every possibility that she could have reconnected with Richard. With Jane becoming the new Mighty Thor, from a storytelling perspective, there needs to be a character that follows her on that journey and reacts to what's happening alongside her.

LEONARD SAMSON

The Incredible Hulk is a largely forgotten entry in the MCU. The movie has been partially salvaged, however, with William Hurt's recent reprisal of Thunderbolt Ross and Martin Starr's strange ongoing role in the MCU. There are a lot of great characters featured in the film, however.

Leonard Samson is one such example. The psychiatrist boyfriend of Betty Ross put himself in the way of the Hulk due to his jealousy over his girlfriend and Bruce Banner. Portrayed by the wonderful Ty Burrell, the character has probably gone through a lot since these events. There's definitely a role in the MCU for a superhero psychiatrist and we could see Samson's superhero alter-ego!

CHRISTINE EVERHART

Christine Everhart has actually been featured in quite a few MCU properties, especially in her role with WHIH, the fictional news station in the franchise. There seems to be a real potential to flesh out this character, who audiences will be familiar with.

RELATED: 6 Characters We'll Miss From The MCU's Spider-Man (& 4 We Won't)

By now, Everhart is probably at the top of her field and looking for the latest scoop on any case Jennifer could be working on. The two could share both a friendship and a professional relationship that could add a new dynamic to the show.

RHOMANN DEY

Dey in Guardians of the Galaxy looking angry

It was mentioned that Thanos had completely wiped out the Nova Corps and the planet Xander during his quest for the Infinity Stones. The means that Dey's family and friends are all likely dead, but there's a real possibility that Dey actually survived himself and is now looking for any kind of revenge in the universe.

In the comics, it is Dey who passes down the moniker of Nova, and this could very well be his role in the upcoming Guardians of the Galaxy Vol 3It's also the perfect way to finally introduce Nova into the MCU.

NAKIA

Nakia on the battlefield in Black Panther

Lupita Nyong'o is an absolute star and it's a travesty that her character Nakia hasn't appeared since the original Black PantherIt is almost certain that she'll return for the sequel, though. Nakia's story was already complex in the franchise, with the activist and spy feeling like Wakanda can do more for the world.

With the events of the last five years, she could have completely shifted in perspective, perhaps feeling like she was wrong and Wakanda should have stayed protected and hidden after its losses. Maybe she feels like even more could be done and it's now too late. Whatever the case, we could see her transition into a more villainous character.

KRAGLIN OBFONTERI

Kraglin

Kraglin's honorary position with the Guardians, his role with the Ravagers and relationship with Yondu have all made him a fan favourite of the galactic series. ,It really wouldn't be surprising if he had an even more extended role in the finale part of the Galaxy trilogy set to release in phase 5.

There's a lot more that Kraglin could do, from rising the ranks in the Ravegers to perhaps even becoming a fully fledged member of the team. Now with the use of the fin and arrow it's clear that James Gunn wants to explore the character some more and give him a larger and more dangerous role.

JANET VAN DYNE

You don't cast Michelle Pfeiffer without having a larger plan for her character. The return of the original Wasp was a big moment for Ant-Man fans, but the character has only since briefly appeared in the funeral scene. However, there must be more that Van Dyne can do in the larger MCU and there's surely a place for her to appear again.

What's strange is that we haven't heard anything about an Ant-Man and the Wasp sequel, which means the places she could appear are limited. But there's still a lot of story to be told there and Peyton Reed is probably eager to get back to work on the characters he loves. Maybe Van Dyne could serve as a mentor figure for a new female hero joining the MCU on Disney Plus?

NEXT: 10 Other MCU Characters Who Might Be Worthy Of Wielding Thor's Hammer