Staff, who played battleaxe Nora Batty for 243 episodes of the BBC comedy, died last week at the age of 80.
Sallis is now one of only two remaining original cast members. Jane Freeman, who plays Ivy, is the second.
Speaking about the late actress, he said: "I'm terribly upset that she's not with us, and I don't know quite for sure whether we are going to do any more [episodes].
"If we do, she is going to be terribly missed."
Staff's TV credits included Emmerdale Farm, Coronation Street, Open All Hours and Crossroads.
Rev Alison Cox from her local church said: "We will miss her terribly. She was a very friendly and warm woman; faithful and generous.
"She was held in great affection by all the parishioners of St Mark's and way beyond the boundaries of our church."