THR – Bill Murray is also circling a role.

Apple is circling Peter Farrelly’s Green Book follow-up, The Greatest Beer Run Ever, with Zac Efron and Russell Crowe now attached to star.

The Skydance project is based on the book by Joanna Molloy and John “Chickie” Donohue, The Greatest Beer Run Ever: A True Story of Friendship Stronger Than War. The movie tells the true story of Donohue, who left New York in 1967 for Vietnam to track down and share a few beers with his childhood friends serving in the Army.

Bill Murray, who worked with Farrelly on Kingpin and Osmosis Jones, is also eyeing a role in the movie, but sources note that his deal is nowhere near to being closed.

A previous package of Beer Run had Viggo Mortensen and Dylan O’Brien attached to star.

Brian Currie, who co-wrote Green Book, and Pete Jones (Hall Pass) will write with Farrelly.

David Ellison, Dana Goldberg, Don Granger and Andrew Muscato will serve as producers. Granger, Goldberg and Aimee Rivera are overseeing for Skydance.

Efron, who is repped by CAA, Alchemy and Felker Toczek, will next film the Three Men and a Baby remake.