Marvel's Avengers: Infinity War is going to be the largest collaboration of on screen superhero talent in the history of cinema. That's no easy task and scheduling can be a nightmare. It's been announced that Benedict Cumberbatch will not be able to make the initial shoots, and therefore will have a stand in to begin production.
When Infinity War begins filming in Atlanta, Cumberbatch will be busy filming The Current War with Spider-man actor Tom Holland. Scheduling constraints will not allow Cumberbatch to make the initial shoots, and he will join the production for reshoots after his work on The Current War is done. His stand in will be Broadway Aaron Lazar according to Page Six. The studio will not use CGI for Cumberbatch's face, instead just reshoot the scenes once he is available.
Avengers: Infinity War will release on May 4th, 2018 and include a number of high profile super heroes confirmed so far. The Guardians of the Galaxy, Spider-man and Avengers have all been confirmed along with Doctor Strange and Captain Marvel, with many more rumored. Tom Holland's role does not appear to be an issue at this time with his scheduling in The Current War.