The actor, who played supermarket manager Reg Holdsworth between 1989 and 1995, also joined a number of former stars who believe that the ITV1 soap lacks the humour of past years.
Morley told The Sun: "They need characters like Reg again. A Holdsworth in the Rovers Return would get people tuning in. There is nothing he couldn't do - a character like that could save Corrie single-handedly by ranting about real issues in the Rovers.
"The executive producer Kieran Roberts asked me: 'Would you ever consider coming back?' I told him I'd come back as a scourge questioning the morals, the views and the thinking of younger people. They really need to get to grips with Corrie or the nation is going to lose a beloved institution."
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Morley joined former co-star Johnny Briggs in saying that he thinks Coronation Street now lacks comedy.
"The Northern humour in the face of adversity is what made Coronation Street great, along with the gritty real-life storylines," he said.
"If it was raining cats and dogs, the character would slip out into the rain and quip, 'turned out nice again'. That's typical Northern humour... That is what the Street was once so good at, making humour out of ordinary situations."
Morley has made a number of appearances in Coronation Street spinoffs since his departure, including last year's DVD Coronation Street: A Knight's Tale.