The Melbourne Demons are quietly confident defender Steven May will be fit in a fortnight.

May lasted less than a quarter of Friday night's successful preliminary final over the Geelong Cats before limping off the park with a hamstring injury.

He did return during the second quarter but looked far from confident on the damaged hamstring before being subbed out of the game for good in the third quarter as the Demons ran away with a monster win.

When briefly interviewed in the post game, May said his hamstring felt "unbelievable."

Despite that, coach Simon Goodwin said the club is "quietly confident" he will be fit and ready to play in the grand final against the winner of tonight's second preliminary final between the Port Adelaide Power and Western Bulldogs.

“We think it might be back-related, he could still move. So we’ll assess that over the next few days, but we’re quietly confident that he’ll be okay,” Goodwin said.

Goodwin also clarified why May had come back onto the ground during the second term.

“Look the game was still in the balance. He’s an important player to us, we felt like it was OK. They felt like it might’ve been back-related, so at that stage of the game it was worth taking the risk," the coach said.

“He got a little bit tighter as the game went on, so we didn’t want to take the risk and we obviously subbed him out of the game.”

It's expected the extra week between the preliminary final and decider could make all the difference for May in his recovery as he fights to play in the biggest match for the club in almost 60 years.

The Demons last flag came way back in 1964, and while they have made two grand finals since in 1988 and 2000, there is a real feeling the minor premiers could finally break the drought this season.