Drax has become a firm fan favorite in his various outings in the Marvel Cinematic Universe. His literal and aggressive demeanor has positioned him as uniquely humorous and intimidating. Taking part in some of the more lighthearted moments in Guardians of the Galaxy, Drax has endeared himself to audiences worldwide. The lighter take on his character on the silver screen has given his character new life. Whether he is launching himself into peril in order to show his combat aptitude or interacting with Baby Groot in silly ways, Drax has been presented as a very versatile and fun character.
With the recent controversy surrounding the expulsion of James Gunn from Guardians of the Galaxy Vol. 3, Dave Bautista's reaction to the aforementioned decision may put Drax's MCU future in jeopardy. Most recently, he has threatened to leave the MCU over the recent events regarding Gunn 's script getting scrapped. It is hard to imagine anyone else in the role, as the wrestler-turned-actor has made it so uniquely his own. We may be presented with a Guardians of the Galaxy movie without Drax if he does leave, as recasting a character so entrenched in the current phase may prove jarring. So who could replace Drax in the team? The Guardians have a wealth of candidates, some even have roots already planted in previous films in the MCU.
The most logical current member of the MCU to slot into the space that Drax would leave is Thor. He made himself more familiar with the cosmic landscape outside of the Nine Realms in Thor: Ragnarok. Not to mention, he was the first Avenger to meet the Guardians. The tone of Thor: Ragnarok was a lot more in line with that of a Guardians film and Chris Hemsworth showed that his comedic timing is perfect for the banter typically found in this format.
During Infinity War, Thor spent some time with the Guardians and then the majority of the film in the company of Rocket and Groot. It would make sense for him to join, and both of the members he's fought alongside could vouch for him. Thor would also provide a lot of raw power to fill the need for a more physical fighter in the absence of Drax.
14 IRON MAN
Tony Stark has proven that he can use his armor to survive leaving Earth's atmosphere, which would be particularly useful when guarding an entire galaxy. Iron Man is another Avenger who has encountered the Guardians, so there won't be any need for an audition. His exchanges with Star-Lord in Infinity War were indicative of an interesting battle of egos that could take place, should he join the team.
There is also the allure of giving Tony access to the technology of the universe. Augmenting the Iron Man suit with some alien tech could lead to some amazing new abilities. Plus, it would be fun to see what sort of things Stark and Rocket could cook up. The addition wouldn't be out of alignment with the comics either, as Tony was briefly on the team before Agent Venom took his place.
13 CAPTAIN MARVEL
Carol hasn't made her MCU debut yet, but it is iminent. Due to her origin and her links to space in general, she'd fit right in with the Guardians of the Galaxy. In the source material, she joined the Guardians for a short while before joining Alpha Flight in protecting Earth. She would add a whole new power level to the rag-tag team, much in the same way Thor does for the Avengers.
Captain Marvel's origin movie is said to be set in the past and she may already be aware of the Guardians. Her links to the Kree through her origin would open up a whole new empire for the Guardians to adventure within. Previously, we haven't seen much of the Kree other than the Guardians' run-in with Ronan in their first adventure.
Whether it is Richard Rider or the fresher-faced Sam Alexander, Nova would be a wonderful addition to the team. We have seen the Nova Corps in action in Guardians of the Galaxy Vol.1, albeit in a less traditional sense. The Corps in the MCU seem to mirror the current comics Corps, in that there seems to be no Nova Force shared between recruits; instead, they appear to be regular space police.
In Infinity War, it is confirmed that Thanos destroyed Xandar to retrieve one of the Infinity Stones. In the comics, the destruction of Xandar is what granted Richard Rider the powers of the Worldmind as the sole survivor of the event. If Marvel used this as a thread to introduce Nova, he'd boost the Guardians' ranks nicely.
11 ADAM WARLOCK
Adam Warlock is on the way! His cocoon is dormant currently, but he's on his way. What role he'll play going into the upcoming films remains to be seen, but speculation is already rife, given his role in the comics incarnation of Infinity War. Regardless, he wouldn't be out of place eventually joining the Guardians.
Adam Warlock is heavily linked to the Infinity Gauntlet and the Soul Stone in particular in the source material. However, once the stories surrounding these objects end, Adam will need somewhere to progress to next. Being a big player on the cosmic landscape, and a former Guardian in the comics, the Guardians of the Galaxy would be happy to have him in their corner!
10 COSMO THE SPACE DOG
Cosmo The Space dog has appeared as part of The Collector's collection in the MCU. He was also seen freed from the collection in a post-credits scene with Howard the Duck. The Russian pooch is a Golden Retriever/Labrador crossbreed who found himself in space following his participation in a Soviet space program. He was somehow rocketed all the way to Knowhere and it is believed that at some point on his journey, he was bombarded by radiation that gave him his powers.
What powers could a dog possibly have? Well, if he's anything like his comic counterpart, Cosmo has powerful psionic abilities including telekinesis and telepathy. Bohze moi! If he ever resurfaces in the MCU, he may find himself appointed a Guardian of the Galaxy.
Scott Lang was recently deputized by the Nova Corps while serving as a Guardian of the Galaxy in the comics, so he seems ready-made for the team in the MCU. His goofy style and improvised heists would make him the perfect partner in crime for Rocket Raccoon. He's also been shown to be able to communicate with the insects of other planets in his cosmic adventures.
Having Scott join the Guardians in the MCU would open up potential adventures to the Quantum Realm, which in the comics is known as the Microverse. One of the Guardians in the comics, Bug, originates from the Microverse. The only concern is that Scott may not want to be away from Earth and his daughter Cassie for too long.
8 BETA RAY BILL
The sworn protector of the last of his people, Bill was found worthy enough to lift Mjolnir. The reason his people needed a protector was that they had been beset by the demon Surtur, the very same Surtur who destroyed Asgard in Thor: Rangarok. In the comics, Bill was given his own hammer, Stormbreaker.
We have seen Stormbreaker appear in the MCU, forged by Eitri, Thor and Groot in Infinity War. We can also see a monument to Beta Ray Bill on the side of The Grandmaster's citadel in Thor: Ragnarok. Bill could still be out there in the cosmos in his trusty ship, Skuttlebutt. It may be only a matter of time before he encounters the heroes, and he could very well join them.
Krugarr would be a very interesting member, should he join the Guardians of the Galaxy. He's appeared as a Ravager in Guardians of the Galaxy Vol.2, so we know he's active and an ally to the Guardians already, following Yondu's passing. What Krugarr adds to the team is a magical element.
In the comics, he gains his magic abilities by becoming Dr. Strange's apprentice in the far future. We see him carrying out magic sigils, so it may be possible he has already met Strange. No matter how he learned his magic in the MCU, he would be an interesting replacement for Drax. Perhaps the Guardians will have to deal with Dormmamu at some point...
Martinex is a member of the original Guardians of the Galaxy in the comics universe. A Crystaline humanoid being, Martinex appears in the Marvel Cinematic Universe as Stakar Ogord's first mate. He is one of the Ravagers who used to run with Yondu before the events of any of the Guardians of the Galaxy films.
Following the death of Yondu, it is possible that the Ravager first mate would step up if the Guardians needed to refill the space left by Drax. Despite his crystal form looking like it can be easily smashed, Martinex is historically very durable. Whether he retains his elemental powers from his comic incarnation remains to be seen, but he has the experience to bolster the Guardians.
The original MCU Yellowjacket was a villain and appears to be dead following the events of Ant-Man. Fortunately for the Guardians of the Galaxy, this Yellowjacket is far less sinister. Rita DeMara's origin in the comics mirror's Scott Lang's, being a kind-hearted thief turned hero. She saved Charlie-27's life, which gained her membership on the original Guardians.
Although long gone, we doubt Darren Cross only had the schematics for the Yellowjacket suit in one place. Rita could steal the plans and progress towards being the new Yellowjacket alongside the Guardians. Fellow original Guardians, including Charlie-27, have appeared as Ravagers, so it is likely that she's also going to make an appearance.
4 STAKAR OGORD
Appearing in Guardians of the Galaxy Vol.2, this Ravager, played by Sylvester Stallone, could be an interesting Guardian. Stakar, like most in the line of Ogord, has the ability to become the powerful being known as Starhawk. If he can turn into Starhawk, this would open up a lot of interesting threads for the Guardians.
In the comics, Stakar's link to Starhawk causes him to relive his life multiple times. This gives him the knowledge of what is to come within his lifetime and he uses this knowledge to try and influence others to create the best outcomes for events. Due to him being a Ravager in the MCU, he may be using this to assist him in committing heists.
3 ALETA OGORD
Aleta Ogord is the sister of Stakar and another member of the Ravagers in the MCU. In the comics, she and Stakar are bonded by the Hawk God that allows them to become the entity known as Starhawk. As only one of them can exist at a time during the union, Aleta spent most of this time in a limbo-existence. The two are eventually separated, with her no longer being able to become the Starhawk.
She is seen in Guardians of the Galaxy Vol.2 alongside her brother, though she looks disheveled. It is possible that she has been affected by the extended time in limbo. The more aggressive of the two siblings, she could more than match Drax's lust for battle.
Bug is a longtime member of the Guardians of the Galaxy in the comics universe. He's an acrobatic fighter, using his insect physiology and a number of weapons, usually a staff. A light-hearted and charming character, he was said to be in one of James Gunn's early scripts for Guardians of the Galaxy Vol.1.
What is intriguing about Bug is that he is from the Microverse. In the MCU, the Microverse is known as the Quantum Realm. As of Ant-Man and the Wasp, we've seen life forms in the Quantum Realm, so Bug might be in there somewhere. We could see him help Scott escape the Quantum Realm following the events at the end of Ant-Man's second solo film. From there, he could join his rightful team.
Quasar is perhaps the most intriguing of the possible additions to the Guardians. Their power level would more than fill a vacuum left by Drax. The Quantum Bands that give Quasar their power are one of the cooler objects of power in the Marvel universe. Quasar hasn't appeared in the MCU yet, but were teased in this cryptic tweet from James Gunn from June last year.
Marvel might have to cast its net wide to find someone to play Quasar, but luckily, there are several iterations of the character Marvel could use. The classic Wendell Vaughn, the Titanian/Kree hybrid Phyla-Vell or the most recent Quasar, Avril Kincaid, could be selected -- and we'd be fine with any of them!