23-year-old rookie Declan Keilty will make his senior debut against Hawthorn on Saturday at the MCG.

Keilty will be the fifth Demon to make his debut from Melbourne's VFL affiliate Casey Demons joining Bayley Fritsch, Jay Lockhart, Tim Smith and Corey Wagner.

Keilty, who was originally named as an emergency for Melbourne, comes into the 22 as a replacement for Tim Smith who will miss this weekend's match due to back soreness.

The key position player has capped a total of 64 games for Casey, signing on as a rookie for Melbourne at the end of the 2017 season.

Keilty's late inclusion will be one of three changes made for Melbourne, with Oscar McDonald and Josh Wagner coming in for Jack Viney (shoulder) and Sam Weideman (Omitted).