The 23-year-old England player said that his career options beyond the sport would have been limited because he was not particularly academic as a youngster.
However, he said that he was always interested in religious studies at school, which might have led to him dedicating his life to the church.
Rooney, who in 2004 admitted visiting prostitutes, told The Sun: "I haven't a clue what else I would have done. I wasn't really the best in school."
When pressed to name another profession, he added: "I always enjoyed RE (religious education), so maybe a priest."
Rooney was speaking at the launch of a campaign sponsored by Coke Zero to find Britain's best young street footballer.
During his career, Rooney has demonstrated that he is perhaps better suited to a career in football than priesthood through several incidents of swearing at referees and being shown the red card.
On Tuesday, the star was also pictured for the first time since he sustained an injury to his left ear when he slipped over on a yacht in the French Riviera.
He needed 45 stitches and an emergency operation after he fell over while on holiday with his pregnant wife Coleen and a group of friends at the beginning of the month.