Sydney Swans coach John Longmire will turn to young stars Isaac Heeney and Callum Mills as he looks to fill the void left by the departure of Tom Mitchell.

Mitchell was traded to Hawthorn in the off-season opening up a position in the midfield for either of the young pair to step into.

Longmire said he was confident there were plenty of players pushing for more senior time through the middle of the ground.

“We knew we’ve got Heeney coming through and Mills coming through and kids like Jordan Foote all pushing for midfield spots and playing through that area of the ground,” Longmire said.

“We’re really confident that we’ve got the players to be able to come in to that role and keep evolving our list like we did last year.

“We had seven debutants last year and I’m sure there will be a number of new players this year.”

Heeney and Mills played majority of their junior football through the midfield before being drafted to the Swans where they have played up forward and in defence respectively.

At 20-years-old the coach is confident Heeney is ready to take the step up of playing more midfield minutes in 2017.

“Heeney, in particular, played a bit more midfield, certainly in the back end of the year,” Longmire said.

“Mills was part need, part teaching last year playing at half-back and just took to it unbelievably well.

“We know Isaac can play midfield-forward and we certainly know Millsy can play midfield-back, so those roles and that flexibility in our team we think is going to be really important.”

The entire playing list returned to the track for pre-season training on Monday and will take part in a solid three week fitness block ahead of a break over Christmas.