Arnold Schwarzenegger chose not to return for "Expendables 4." He revealed in an interview with Parade that he declined the opportunity to reprise his role as Trench Mauser, a character he played in previous "Expendables" films. Schwarzenegger told his co-star and the former director/writer of the franchise, Sylvester Stallone, that he wouldn't be returning, stating, "It's done, and I'm not in it."