Avengers directors Joe and Anthony Russo already admitted that the Avengers 4 title was too revealing to release straight away.
They said it would not be disclosed until suitable time had passed after Infinity War hit cinemas.
Marvel has no official presence at San Diego ComicCon this year, nor is there a Disney D23 expo.
However, next week a huge international cinema event takes place in Barcelona for distributors, financiers and studios.
MCUCosmic said: “Next week, starting on Monday, is a big theatre exhibitor’s convention in Spain called CineEurope. This is pretty much the same thing as what we just saw in Las Vegas with CinemaCon, and there will be another in Florida this year with ShowEast. This is where movie studios present their upcoming movies to exhibitors to hype them up about playing the films in their theater chains.
The Walt Disney Studios is making their presentation Wednesday the 13th at 4:45pm.”
This will be 3.45pm in the UK.
A recent leaked promo art image of Avengers 4 heroes geared up for battle is now reported to be for the same event.
MCUCosmic added: “Avengers 4: This is the big one. That leaked promo art that some people tried to claim as fake was actually produced for this event. Presumably they’ll display it on the screen as they hype up exhibitors about next May’s release.
“There probably won’t be any footage, but it’s possible they may drop the title here. If that happens, that will be the huge news out of the convention. Even if it doesn’t happen at CineEurope, people who know what the Avengers 4 title believe it will likely be leaked by someone within the next week.”
The site previously revealed that a Captain Marvel teaser trailer has already been put together, however this is unlikley to be shown at CineEuroope 2018.
MCUCosmic explained: “Instead, they’ll do what they did with Infinity War last year and show a behind-the-scenes reel and some production stills.”
Either way, it looks like next week will include two potentially headline-grabbing Marvel reveals.