"Evil Dead"-actor Bruce Campbell was Kripke's first choice to portray the character. However, Campbell was unavailable, and Jeffrey Dean Morgan eventually received the role. Due to the fact that Morgan's scene in the pilot episode takes place 22 years before the series, Morgan expected to be replaced by an older actor for subsequent episodes. Being only 12 years older than Jensen Ackles, who portrays the eldest son Dean, Morgan was surprised when he was asked to reprise the role. Ackles and Jared Padalecki often teased him about the age difference during filming. Throughout the season, Morgan became frustrated at times due to his character's avoidance of his sons, stating, "It pissed off everybody, it pissed off us as actors, it pissed off the audience watching, because none of us really knew where we were gonna go." However, he reasoned that John's motivation for his actions was due to having knowledge that nobody else had.