Veteran forward Ellison fired 17 goals last season despite nursing a persistent back problem and a run of five in his last four outings means he has already reached 10 this term.
Shrimps goalkeeper Roche believes the well-travelled 33-year-old's influence is invaluable for Jim Bentley's side, who lie 16th in League Two heading into the festive period
"He's a massive player on and off-the-pitch," Roche told Press Association Sport. "He's such a lively character in the dressing room as well.
"The amount of goals he's scored for us in the last two seasons, I dread to think where we'd be without him. He's been so important for us.
"Long may it continue. I think last season was the most goals he'd scored in a season, he's more than halfway towards reaching that target again and we hope he can."