Michelle was recently tipped for a new relationship story, causing many fans to suspect that she would fall for Carla Connor's brother Rob Donovan when he joins Weatherfield.
However, Marsh told All About Soap: "New man? It's actually more of an old man. Could she be getting closer to a certain Mr McDonald again? Maybe!
"I think the viewers are expecting Michelle to get it on with Rob because he's the new guy, and the last person they're expecting her to pair up with is Steve."
Marsh said that Steve (Simon Gregson) will help Michelle out when she learns that her son Ryan is heavily involved in drugs.
"Steve has always been very much part of Ryan's life from when he was with Michelle before, and we'll see him being a massive support for her," she confirmed.
"Can you imagine what that would do to Tracy? The cat fights would be amazing. But I think Michelle would beat Tracy hands down!"
However, Marsh added that she would not want a reunion between Michelle and Steve to become too "serious".
She commented: "I don't want to see Michelle getting serious with a guy. I like her relationships as long as they keep them quite light and fresh. Michelle's a drifter, but I love that about her."
Michelle and Rob will be running the Underworld factory together after Carla flees Weatherfield with Peter Barlow in an upcoming storyline.