Summer Bay's current reverend, Elijah Johnson, left recently following Jay Laga'aia's controversial sacking.
McGranger, tipping Irene for the vacancy, told the Channel 5 website: "I've never said this to the writers.
"But given what Irene's been through - and she's always had a vague Catholic religious way - I thought I would like her to become a little bit more involved in that side of things.
"Maybe [she could] do a theology course or something and become a local pastor. Maybe a little bit of Vicar of Dibley."
The 59-year-old added: "I think she already is a little bit like that. She certainly has been known to send up a prayer in times of trouble."
The Summer Bay stalwart recently battled breast cancer.
McGranger is the second-longest serving cast member in the Australian soap, having joined in 1992.