MELBOURNE is weighing up whether to blood tall defender Harrison Petty for its Queen's Birthday clash with Collingwood at the MCG.

In-form forward Jake Melksham (ankle) is expected to play against the Magpies, but will not train on Friday to prepare himself for a fitness test on Sunday.

South Australian 18-year-old Petty has been included in a preliminary squad of 26 players for Monday's game alongside athletic backman Joel Smith, who is also in the frame to replace the injured Jake Lever, who is out for the remainder of the season with a left knee injury.

Petty, pick No.37 in last year's NAB AFL Draft, has been promoted ahead of the more experienced Sam Frost, and coach Simon Goodwin said the youngster deserved an opportunity to play if selected.

"He's an exciting young player. He plays key position and he's really improving as a player, and he plays with a competitive spirit. He's someone we're certainly considering closely," Goodwin said.

Petty has impressed for the Casey Demons in the VFL, especially with his ability to pick up Melbourne's defensive concepts and play his role in the system the club is trying to implement.

The 197cm youngster had a slightly interrupted start to his career at Melbourne after he fractured his elbow tripping over a wire fence while on a run prior to last year's Draft.

Cameron Pedersen is in the running to play his first game since round two after stellar form at VFL level, and is being considered as a replacement for the omitted Tim Smith.

While Smith had been battling a neck complaint and also had a sore ankle, Goodwin said the competition for spots meant a change needed to be made.

"It's probably form," he said.

"We felt last week that he lacked a bit of impact, but we've also seen what he can produce as well. It's really competitive for spots. We've got some guys at VFL level who are really pressing for selection and that's a great thing for our footy club."

After dropping his infamous 'fugazi' line at his press conference last Friday, Goodwin said it was all business ahead of Monday's game.

"There's no mantra this week. It's just about getting out there and playing our best footy," Goodwin said.

"That's first and foremost. It's really about getting our club and our players to be at their best on the big stage."

Freeze MND champion Neale Daniher will speak to the Melbourne players later on Friday to offer his inspiration and insights, with Goodwin expecting a grand stage on Monday.

"You can feel the excitement. It's everywhere you go. It's a great game to be a part of. It's a great cause, but it's also two really great teams playing some terrific footy," Goodwin said.

"We're looking forward to it and I know Collingwood are as well. We're looking forward to getting a big crowd there as well."

As for the costume Goodwin will don as he plunges into the icy water alongside the other 17 AFL coaches prior to the game: "I heard 'Melky' (Melksham) threw me under the bus (when he suggested Goodwin should wear Speedos). We put it out to our fans so it's going to be pretty close to the Melbourne supporters' heart, but I promised my 17-year-old daughter that I won't be going down in anything embarrassing."