MELBOURNE coach Paul Roos has given every indication key defender Tom McDonald will put pen to paper and remain at the club.

The out-of-contract 23-year-old is yet to recommit to the Demons following his breakout 2015 season that saw him finish third in the club's best and fairest – for the second time – and soar into All Australian calculations. 

Despite the uncertainty surrounding McDonald's playing future, Roos believed the backman would "definitely stay" at the Demons.

"It's hard to talk about specifics because part of it now I'm not involved in, but I think Tom will stay," Roos told Fox Footy on Monday night.

"I think Tom sees a real direction of the club.

"I guess we very rarely see players leave – family connections going back home, certainly; money I still don't think necessarily comes into it.

"There's got to be a reason for a player to leave and I think Tom will definitely stay at the footy club."

In June, McDonald told his main intention was to play "good footy and (the contract) can be worked out along the way".

He played his 100th game in Sunday's thrilling two-point win over Gold Coast at the MCG and is averaging just under 19 disposals in his 18 appearances this season.

McDonald's younger brother, Oscar, has also become a regular member of the Demons' line-up, featuring in every game since round nine.