Captain Marvel star Jude Law may be playing a villain lurking in plain sight. As revealed by Entertainment Weekly, Rogue One star Ben Mendelsoh's role was confirmed to be Talos, a Skrull leader, and not Yon-Rogg, as was widely believed -- but don't count Yon-Rogg out just yet. Given the mystery surrounding Law's role and his position within the film, it's entirely possible he will play Yon-Rogg instead of Mar-Vell.
Despite all of the Captain Marvel news that just dropped, Law's role in the film is still a secret. This, in and of itself, implies Law isn't Mar-Vell, like most fans expect. If Marvel had revealed Law as Mar-Vell, it would have been notable -- but not much of a surprise. After all, he has been rumored to play Mar-Vell since he was cast last fall. Having already revealed other major players like Talos and Ronan the Accuser, Marvel has no reason to keep Law's part a secret unless there's a much bigger surprise in store.
Instead, Law's character is described as "the commander of Starforce" and "a mysterious mentor" to Carol Danvers. Notably, the comic book version of Carol Danvers has crossed paths with another major Kree officer: Yon-Rogg. In the comics, Yon-Rogg is Mar-Vell's commander on the Helion, a Kree ship sent to Earth by the Supreme Intelligence. However, unlike Mar-Vell, Yon-Rogg was always hostile towards Carol. In fact, he tried to kill her -- and later Mar-Vell -- for their friendship, deeming it "Un-Kree."
Further, Yon-Rogg worked closely with Ronan the Accuser in the comics. Together, the two engaged in a plot to overthrow the Supreme Intelligence and install Ronan as the new Kree overlord. As evidenced by photos from the film, Law's character will indeed work with Ronan, but in what capacity is unclear.
Additionally, it's worth nothing that Yon-Rogg was present for a critical moment in Carol's life: the manifestation of her powers. In the comics, Carol was a normal human woman until her path crossed with Mar-Vell. In one of Yon-Rogg's attempts to kill them, he triggered the destruction of a device called the Psyche-Magnetron. In the ensuing explosion, Mar-Vell’s genetic structure was grafted onto hers, leading her to become part-Kree. This blend of Kree and human DNA granted her powers, ranging from power absorption to flight. Since the film will explore Carol's origin, it wouldn't be surprising to see this critical moment on screen, nor would it be a shock if Yon-Rogg was involved.