While there will be a little less Danger for the Demons at the MCG, given Cats star Patrick Dangerfield is out with a hamstring injury, Ablett is the X-factor that could swing the match.

The 33-year-old is back at Geelong after seven years at Gold Coast.

A hamstring injury means Ablett didn't play in the pre-season.

That, and his age, means there is some doubt over what impact he will have against Melbourne - but not according to Cats coach Chris Scott.

"His preparation has been really good by his standards," Scott said.

"He tends not to need to play official pre-season games to get himself right to play well (and) I think his round-one record is pretty good.

"We do value the match practice that we get in our training and he's done a lot of that.

"I don't want to be overconfident but he'll step into the midfield and play his normal role. That's the plan."

One of the many fascinations with Ablett is how much time he'll spend in the middle compared with how often he goes forward.

Scott made it clear that when Ablett plays in attack, it will not be to rest the veteran.

"There's no specific plan to protect him, if that's the right word," Scott said.

"If he's forward it will be more with a view to him being a weapon there, rather than limiting his midfield minutes."

Three Cats will make their AFL debuts on Sunday - Tim Kelly, Esava Ratugolea and Lachie Fogarty - as Selwood plays his 250th match.

The Demons surprised by leaving out Angus Brayshaw and Dom Tyson.

Former Adelaide defender Jake Lever and newcomer Bayley Fritsch will officially wear red and blue for the first time after impressive pre-seasons.

The Demons had bad news during the week when co-captain Jack Viney and Tom McDonald were ruled out for up to two months with foot injuries.

Australian Associated Press