Paul Mescal’s next major project looks set to be Sam Mendes’ much-discussed four-part biopic film series about the Beatles for Sony Pictures.

The casting — which was first rumored in the summer — was brought up by Mescal’s “Gladiator 2” director Ridley Scott in a conversation with Christopher Nolan on Tuesday at the Directors Guild of America, in which he said “Paul is actually stacked up, doing the Beatles next.” Sources close to the production have since confirmed to Variety that Scott wasn’t speaking out of turn and Mescal — while not officially signed up as of yet — is indeed attached to the project.

Mescal is now widely expected to play Paul McCartney across four biopics Mendes is developing and will direct about the Fab Four, each focusing on a different band members and being released theatrically. The project — being produced by Mendes’ All3Media-owned production company Neal Street — was first unveiled in February,...