Ben Mendelsohn has been tipped to play the main antagonist of "Captain Marvel" since last month. Although Marvel has not yet confirmed his casting, fans were quick to assume he will be playing a Skrull. However, a new report claims he will actually be portraying a Kree military officer.

According to The Hashtag Show, a source close to the production said Mendelsohn's involvement is pretty much a done deal. The actor has reportedly agreed to board Marvel's first female-led superhero film likely as Colonel Yon-Rogg. THS notes the screenplay still has a lot of "moving parts" at this point, but the character's inclusion is said to be already set in stone.

Created by Stan Lee and Gene Colan, Yon-Rogg debuted in "Marvel Super Heroes #12" as one of Mar-Vell's fellow Kree military officers. Just like the latter, Yon-Rogg was originally tasked with observing Earth for the Supreme Intelligence and detecting any human activities that may be a threat to the Kree Empire. However, his deep hatred toward Mar-Vell due to his romantic relationship with the Kree Medic Una turned him into the original Captain Mar-Vell's formidable nemesis.

Yon-Rogg is not exactly an unexpected choice to be the film's big bad given how strong his character's connections are with Carol Danvers' origin. In attempt to kill Mar-Vell, who was living in human disguise and working at a scientific facility as Dr. Walter Lawson, the Colonel held Danvers as hostage. Danvers was caught in an explosion, which fused her and Mar-Vell's DNA. This gave her superhuman abilities, paving the way for her to become the next Captain Marvel.

Screen Rant notes that "Captain Marvel" is expected to deviate from the source material to some degree, but it should retain some important elements from the character's backstory. Regardless of Mendelsohn's involvement, Yon-Rogg could very well be one of those that will be included in the live-action adaptation. After all, Mar-Vell is also appearing in the film with Jude Law portraying the role, so the villain's appearance is all the more likely.

Then again, this is just pure speculation for now, so it is best to be taken with a grain of salt. If Mendelsohn does land the role, "Captain Marvel" will mark a reunion for him and directors Ryan Fleck and Anna Boden whom he worked with in "Mississippi Grind."

Starring Brie Larson in the lead role, "Captain Marvel" is slated to debut in theaters on March 8, 2019.