MELBOURNE is set to make a couple of changes for Saturday night's game against Fremantle in Darwin as it looks for vast improvement defensively to arrest a three-game winning slump.

The Demons gave up 18 goals (119 points) to the Saints last Sunday, with coach Simon Goodwin expressing his frustration to his players during the team's review of the game earlier in the week.

Since round 12, the Demons rank as the worst side in the competition for points conceded (109 points) and Goodwin said there was no quick fix.

"It was pretty clear in my post-game (press conference) that I thought the problem was in our defensive transition and clearly that's our biggest growth area," Goodwin said.

"We highlighted it at the beginning of the year and at the weekend it came out.

"We're really clear internally what our issues are and how we're going to continue to get better."

Goodwin refused to blame Melbourne's defensive struggles on the loss of star defender Jake Lever, who will miss the rest of the season after rupturing the anterior cruciate ligament in his left knee.

"We'd prefer him out there, because he's a quality player," Goodwin said.

"But it probably took Jake three or four weeks to really settle into the back six and it was those inconsistencies with our pressure on the ball and our defensive transition.

"With Jake there or not there we need to commit to the defensive actions required and we're bullish that we can turn that around."

Youngster Oskar Baker is in the frame to make his AFL debut after gathering a season-high 34 disposals for Casey in the VFL on Saturday, while veteran Bernie Vince (25 disposals) performed strongly following his demotion to the VFL.

Goodwin also backed veteran defender Jordan Lewis to respond accordingly after criticism levelled at him for his defensive output.

"Jordy's an incredibly strong leader for our footy club. It would have been a really tough day last week playing in our back six and Jordy was a part of that," Goodwin said.

"He's someone we really value in that position; he's someone who was really strong for a seven-week period in our back half and we're confident he can still play really high level footy."

In positive news, Aaron vandenBerg and Pat McKenna have been confirmed to play their comeback games for Casey on Saturday after being sidelined long-term with a foot and hamstring injury respectively.

"It's fantastic. Eighteen months on the sidelines for both of those guys. They're really pivotal to our playing group, they have a great impact and have really grown in that time," Goodwin said.