Clark Gregg's Phil Coulson is, so far, the only one from "Agents of S.H.I.E.L.D." who has appeared in the Marvel Cinematic Universe (MCU). However, that might change soon.

A recent social media posting shared by an MCU actor sparked rumors that another character is crossing over from the television to the film universe. The character in question is none other than Gabriel Luna's Johnny Blaze aka Ghost Rider who debuted on Marvel's "Agents of S.H.I.E.L.D." last season.

The actor recently posted a photo of himself sitting next to Frank Grillo on an airplane. Grillo played the role of Brock Rumlow/Crossbones in a few Marvel films.

The image has no clear caption save for some emojis and hashtags, so it is unknown whether both actors are headed somewhere together or they just they ran into each other by accident. However, with production for "Avengers 4" currently happening in Atlanta, there are speculations that they may either be going to or coming back from the set.

It is worth noting though that Grillo, although spotted in Atlanta recently, is not yet confirmed for the fourth installment, so it is best to take this rumor with a grain of salt.

That said, Cosmic Book News says Ghost Rider's appearance on the MCU may now be possible, considering the internal changes happening within Marvel like the fact that CEO/Chairman Ike Perlmutter is no longer involved with the movies. For years, President Kevin Feige has reportedly had frustrations over his creative interference.

Although the TV arm of Marvel still reports to Perlmutter, the publication notes there have been rumors he may be stepping down soon. Plus, Marvel's TV unit, which directly reports to Perlmutter, has enjoyed far less success than the MCU. With Disney's upcoming new streaming service, the company may have finally started bringing all of Marvel under one umbrella.

Further proof is that Samuel L. Jackson, who played S.H.I.E.L.D.'s Nick Fury in the previous films, along with other people from the same organization, are making their comeback in the movies. Then again, the publication clarifies that these are all pretty much guesswork at this juncture.

Marvel Studios and Marvel TV are still separate units. For now, fans can only keep their fingers crossed and wait until "Avengers 4" to confirm the claim.

The fourth installment is set for release on May 3, 2019.